Has Paris met his match on the rails?

The chief of Jarvis has surged ahead by winning track-maintenance deals. But now the contracts could undermine him

Paris Moayedi isn't your typical British company boss. Raised in the mountains outside Tehran and trained in Bradford, the chief executive of Jarvis shares few characteristics with his grey-suited counterparts. Associates describe the 63-year-old as hot-blooded and aggressive, while critics say he can be slippery and difficult. "You always have to count the fingers on your hands after dealing with him," says one former sparring partner.

Like its leader, Jarvis isn't just an average engineering firm.

At the centre of the investigation into the Potters Bar rail crash, with responsibility for the faulty points, Jarvis is also Railtrack's biggest maintenance contractor. It is involved in the controversial part-privatisation of the London Underground as well as operating a plethora of Private Finance Initiative contracts.

The workload is all Moayedi's creation. When he took over in 1994, Jarvis was a construction and property firm worth £2m. Now placed at the heart of New Labour's privatisation programme, it is worth £534m.

That was last week. A fortnight ago, it was worth over £700m. But then its shares slumped as a result of the Potters Bar crash.

It's a familiar story. Over the past few years Jarvis has endured unwelcome headlines – a row with Railtrack here, a spat with its auditor there – that have temporarily knocked the wind out of its shares. But with half of its revenues coming from fixing the rail network and its heavy exposure to the PFI, the City has always gone back for another fix of Jarvis.

Now, however, there are niggling fears that Moayedi's luck may run out.

Some £425m of Jarvis's revenues come from rail maintenance. Of the seven companies that have contracts with Railtrack, it enjoys one of the best reputations, investing generously in staff and machinery. Nevertheless, Railtrack and Jarvis have not always seen eye to eye.

One senior Railtrack source says: "We used to joke that it was 'Paris in springtime' because at the year-end Paris would always come in with a string of cost overruns."

Railtrack's successive chief executives have had varying relationships with Moayedi. While some disliked his aggressive approach, Gerald Corbett got on well with the Jarvis chief.

But it is understood that shortly before he resigned, Corbett had decided the only way to solve the problems of the railways was for Railtrack to take back full responsibility for maintenance. This could have devastated Jarvis: half its business would have disappeared and thousands of employees been transferred to Railtrack.

Luckily for Moayedi, Corbett's successor, Steve Marshall, never implemented the plan and Jarvis has since enjoyed a share of Railtrack's 21 per cent increase in spend on maintenance and renewals.

But there are new threats to Jarvis's lucrative rail assignments. Railtrack wants to strip its contractors of their responsibility for safety on the track. The reduced role could lead to a much smaller fee.

Railtrack's chief executive, John Armitt, has already held informal discussions with the Health and Safety Executive about the plan and is expected to make a formal application in the summer. If approved, Network Rail, the company bankrolled by the Government to take over Railtrack, would operate the system.

Jarvis still has an ace in its pack. In the aftermath of Railtrack being put into administration, Moayedi was quick to spot the significance of the Network Rail bid, and Jarvis became the group's technical adviser. While Network Rail will show no favours to Jarvis for the work it has done, "it certainly won't have done any harm," says one source close to the bid.

A senior executive of a rival contractor says that this is typical of Jarvis: "getting to the centre of affairs" and not worrying about what could be seen as a conflict of interest.

The company's sometimes pushy approach has helped it win contracts, but some in the City are still uneasy about Moayedi. This goes back to 1999 when Jarvis traded blows with Railtrack over £12m the contractor claimed it was owed. Eventually Jarvis backed down, but the affair still sticks in the minds of City analysts.

Chris Bamberry at Deutsche Bank says: "Jarvis gave too little too late. Moayedi should have told investors of the problem much sooner."

A year later he was embroiled in another public spat, this time with auditor PricewaterhouseCoopers.

PwC had suddenly quit, citing a disagreement over fees. Its resignation letter filed at Companies House was withdrawn when Jarvis claimed it was defamatory.

When Moayedi became chief executive, the firm was on the brink of collapse, suffering from the downturn in the property market. He set about reshaping Jarvis, with the acquisition first of Northern Infrastructure Maintenance Company and then Streamline Holdings. Today he is the fourth-largest shareholder in Jarvis, with 3.9 million shares, making him a paper millionaire some 14 times over.

His trappings of success include a 15th-century thatched cottage in Essex and a house on the beach in the Cayman Islands, a far cry from his early years as a civil engineer. Moayedi left Iran at 20 to study at university in Bradford, where he met his future wife in the Mecca dance hall.

He joined the construction company Amec, where at 28 became the youngest-ever contracts manager. After working for housebuilder Walter Lawrence and then running his own business, he took the reins at Jarvis.

Today, insiders say his personality dominates the company and few decisions are taken without his involvement or say-so. But in the coming months this tough personality could face his toughest test yet.