Has the Conran era come to an end?

The name of Sir Terence Conran is so evocative of smart restaurants and stylish shops selling modernist goods to discerning customers that it seems odd that his long, fabulous career – now apparently coming to an end – began in the years of austerity and ration books.

Even those who are aware that Sir Terence has been influencing public taste for a very long time think of him as a product of the Swinging Sixties, an innovator and tycoon who brought style and taste within the price range of the average office worker. His restaurants, now up for sale, are commonly thought to be the means by which he reinvented himself after being prised out of the business of running fashionable high street shops.

But the first premises opened for business by the young Terence Conran, in 1953, was his Soup Kitchen, where a bowl of soup cost a shilling. The difference between that and the soup kitchens associated with the Great Depression was the minute care over its interior design, with simple fittings and large pictures of old engravings on the wall. There was then only one Gaggia machine serving coffee anywhere in London. Conran's Soup Kitchen raised the number to two.

But before we go further into the long history of Sir Terence's life and times, here is interesting news for any Russian oligarch or anyone else out there with a lot of spare cash. There is a unique chance on offer to become one of the biggest names in London's gastronomic scene, for a price of around £100m. The celebrated Conran restaurants are up for sale.

They include Le Pont de la Tour, that beautifully located eating hole in a renovated wharf on the south bank of the Thames near Tower Bridge, in a back street that cannot be reached by taxi, where Tony and Cherie Blair entertained Bill and Hillary Clinton. There is also Bluebird, patronised by Prince William's girlfriend, Kate Middleton, and Quaglinos, which was a rat-infested derelict shop in a Piccadilly side street before Conran moved in.

But now the 76-year-old entrepreneur who has done so much to influence the way smart Britons eat is clearing away the dishes of his business empire. The City bankers Goldman Sachs have been hired to find a buyer for Sir Terence's 51 per cent share of D&D, London, the holding company that owns his London properties, and others in New York, Scandinavia and Tokyo.

These restaurants are expensive places to eat only in the general way that all quality restaurants in the capital are expensive. If you can afford to eat out in central London at all, you can afford a seat at one of Conran's tables. Certain connoisseurs of good food have been sniffy about the cuisine. The compilers of San Pellegrino's list of the World's Best Restaurants include only three UK troughs in the top 50, none of them Conran's.

His selling point is the unique environment he has created. Everything in a Conran restaurant, from the font used on the menu to the layout of tables and the decor, pleases the eye and flatters the customer. It is no wonder Edina and Patsy, of Absolutely Fabulous, made Quaglinos their restaurant of choice: its ethos would have reassured that they were modern women of wealth and taste.

"Going out to a restaurant is not just about eating," his former collaborator, the design guru Stephen Bayley, said yesterday. "It's about people, and atmosphere. The very best restaurants capture that. People go to a restaurant as an experience in interior design. Terence gave them that.

"When I first came to London, straight out of university, there were 10 or 15 decent restaurants in London. Now there are 10,000. I'm not saying Terence created that single-handed, but he was a major part of it. It's an important moment in popular culture when Terence Conran gives up control of his restaurant interests." It is hard to credit that after more than 50 years, he has really given it all up. Whatever Sir Terence wanted, whether it was money, recognition, or job satisfaction – he accumulated more than enough of that to satisfy any normal ambition many, many years ago. But this is a man driven by a love of something new to do, whose life's mission has been the "democratisation of luxury". You feel that, even now, some sort of Conran design or innovation ought to be in the offing.

It is often the way, that people value most what they were denied when they were young. During Terence Conran's boyhood, fine furniture could only be found in the wealthiest homes, where it was passed from generation to generation. Food eaten for pleasure rather than sustenance was even more rare. People's money went on necessities, and if there was any cash to spare, they spent it on what little was available.

Born in 1931, he had his eighth birthday a few weeks after Britain went to war. In 1948, during post-war rationing, having just left Bryanston, in Dorset, one of the more progressive public schools, he was already designing and selling textile prints as a first-year student at the Central School of Arts and Crafts.

It was to be one of the criticisms of this energetic, highly imaginative individual that he was better at starting projects than sticking to them. An early sign of this eagerness to rush on to something new was that, two years into his three-year design course, he was off, to join an architects' practice that had been commissioned to design the interior of a quarter-scale model of a flying boat for the 1951 Festival of Britain.

The festival, he later claimed, was what first prompted the post-war British public to think about things they would like to have, rather than what they needed. His life's mission was to introduce aristocratic good taste to the middle class, at a price they could afford. But in the 1950s, the average shopper sunk whatever spare cash there was into labour-saving goods such as washing machines, so the Conran Design Group, founded in 1956, had to exist on commissions from corporate clients.

It was not until the 1960s that there were enough young people about with the money and education to buy large quantities of the elegant goods that Conran wanted to sell them. His first furniture factory was opened in Norfolk in the year British teenagers discovered the Beatles. The first Habitat shop was opened on London's Fulham Road, on the site of an old pub, on 11 May 1964.

Conran pioneered the notion that when people buy furniture or kitchenware, they are not just looking for something useful – they are expressing something about themselves, and buying into an attitude to life. He wanted to make quite sure that people caught the connection between Habitat's self-assembly furniture and pots and pans, and the era of rock 'n' roll and holidays abroad. So he hired Mary Quant to design the uniforms worn by his shop assistants, and Vidal Sassoon to cut their hair, while Terence Donovan took the pictures at the shop's opening.

Success was immediate. People liked the flat-pack self assembly furniture piled high in space that was like a cross between a shop and a warehouse. By 1968, there were four Habitat shops in London, and a fifth in Manchester. By 1973, there were 18 in the UK, including the largest yet, in the King's Road, west London, and one in Paris. The forerunner of the famous Habitat catalogue was Terence Conran's Original House Book, published in 1974.

In 1981, he floated Habitat on the Stock Exchange, a move that generated capital but opened him to the risk that he would eventually lose control of his own creation. At first, it allowed him to expand into education, through the Conran Foundation and later through the Design Museum, and into every high street, by buying Mothercare, a chain of more than 400 shops, in 1982. He teamed up with the head of the Hepworth menswear chain to create Next. In 1986, Sir Terence, as he now was, pulled off the biggest coup of his business career, by merging Habitat-Mothercare with British Home Stores.

Although he was never a great admirer of Margaret Thatcher, he had done well out of the business atmosphere she had helped create, and his fall from grace as a high street retailer coincided with her political demise. Always better at generating new ideas than keeping old ones going, he lost control of the company he had built up, and he retreated to an office in Butlers Wharf, on a stretch of the south bank of the Thames that he had helped to renovate. From there, he decided to go back to the restaurant business, hoping to make the diners who used his restaurants feel that they were members of a club, united by good taste, just like those young couples who patronised Habitat in the Sixties.

"In Habitat, he came across a formula for furnishings that exactly fitted the needs of that generation, who were the first people who did not inherit furniture but had had a university education and had good jobs," Stephen Bayley said.

"There is a famous story that when he took over British Home Stores, he exclaimed – 'What is that awful pink nightie? Get it out of here!' – and they had to say 'Actually, Sir Terence, that is our best-selling line'."

But the end of the Conran era, he suggested, has been a long time coming. Many thought it was over when the great innovator's flirtation with the City turned sour in the late 1980s, and he lost control of the "darling" he had created in the 1960s.

"He used the same architectural formula when he opened his restaurants but they didn't quite have the sort of match with the customers.

"Terence's taste is educated, middle class and Chelsea. It only really coincided with a small percentage of the population. His restaurants were populated by people Terence didn't know existed. In the end, they became the sort of mediocrity he was trying to escape, and I sort of wish he had retreated some time ago. In a certain sense, the news that he is pulling out has been a long time coming, but it is elegiac. He has been a major figure in British cultural life for 52 years."