The National Westminster Group may not have a Michelangelo in its collection of 1,500 artworks, but it does own a wondrous collection of British paintings, ranging from portraits by George Romney and Sir Joshua Reynolds to a sizeable and representative portfolio of 20th-century art. A wealth of work by Frank Auerbach, David Hockney, Ivon Hitchens and Howard Hodgkin continues up to the minute with paintings by Simon Lewis, Callum Innes and Mark Francis, a catholic assembly of landscapes, figurative work, abstracts, constructions and photography. Outside the major galleries, this is as good a guide as you will find to modern British painting, and a reminder of the powerful links forged between wealth and art over four centuries - the earliest works were commissioned by banks founded in the Tudorbethan years, before amalgamations spawned today's oligopolies.
Next Wednesday, the collection goes on show to the public for the first time in NatWest's new Lothbury Gallery in the City of London. There should be no doubt in the minds of the bank's clients and shareholders that it has invested wisely in art, particularly over the past 40 years.
The marble gallery, currently ablaze with the incendiary colours of Auberbach, Hodgkin and Caulfield, is housed in the central court of NatWest's opulent headquarters, across the street from the Bank of England. The architecture is by Charles Mewes and Arthur Davies - best known for the Ritz Hotel in Piccadilly, the RAC Club in Pall Mall, and the Cunard Building in Leadenhall Street. Appropriately, it's in High Italian Renaissance style, dating from 1932: lofty Ionic columns of cream Subiaco marble supporting a glazed roof. The court was a banking hall until business was transferred 15 months ago to nearby Lombard Street, home of the Lombardy money-changers who came to England with William the Conqueror. The first show, of some 50 paintings hung from simple, moveable screens, has been culled from the office walls of bank executives ensconced in NatWest's major post-war monuments. In fact, the NatWest is not the only bank to own hidden art collections: Hambros, for example, has pieces by Sir Jacob Epstein, Augustus John and Joseph Wright of Derby ("Edwin"), and Barings has works by Duncan Grant and Wilson Steer. But, unlike the pair of Canalettos and 22 other Old Masters sold this month by the British Rail Pension Fund, none of the NatWest collection was acquired as an investment, insists Rosemary Harris, curator of the gallery. Its function was simply to brighten regimental headquarters.
Harris, who previously worked at the Tate Gallery, has had a free hand in shaping the first new public gallery in the City of London for more than 20 years. At a time when high street banks are presenting a stony face to many small investors, David Edmonds, managing director of NatWest's Central Services, who is in charge of the Lothbury, expresses pride in the collection - "and, in any case, returns on investment don't come much better than this".
To begin with, the gallery will only be open on weekdays, a reflection of the City's age-old aversion to weekends. For decades, the "Square Mile" has been the world's most magnificent ghost town between close of play on Friday and tills opening on Monday morning. Change, however, is quietly underway. NatWest itself has been encouraging and investing in new homes within the boundary of the old City walls. There is plenty of space for flats in the upper floors of the City's marble and Portland stone palazzos, while the area leading north of the City through Smithfield Market to Clerkenwell is re-populating at a quite remarkable rate; remarkable, that is, for a quarter which appeared condemned to urban wasteland just a few years ago.
"When the demand is there," says Edmonds, "we will happily open the gallery to the public at weekends. We hope that shops will follow." Such measures would bring tourists in their wake, although the Lothbury Gallery's Christ Driving the Photographers from King's College Chapel (Elisabeth Vellacott, 1981) appears to hint at the City's intolerance of curiosity seekers.
In the meantime, Harris will be free to buy and sell paintings as she sees fit. In recent years, the bank has been buying the work of young artists such as Lewis, Innes, Francis and Antoni Malinowski, and continues to sponsor the NatWest Art Prize, which this year will pay out a total of pounds 36,000 to winning entrants.
The Lothbury mitigates the relentless blandness of modern bank interiors, and puts private art on public show. Put your cheque books away; even if you can afford Victor Pasmore's Linear Image No IV or Gilbert & George's Nature Queens, they are not for sale. By banker's order.
Lothbury Gallery, 41 Lothbury, London EC2
10am-4pm (last admission 3.30pm), Monday to Friday, starting 12 February. Admission free