Not many aspiring entrepreneurs produce ideas sufficiently compelling to interest George Soros. But Robin Priest, one of the pioneers of property out-sourcing in Britain, had a business proposition that captured the imagination of the legendary Hungarian investor.

In early 1999 Priest, a former Bank of America executive, took his plan to bid for and run the property assets of the Inland Revenue and Customs and Excise to Richard Georgi, one of Soros's executives.

Georgi like the idea and thus was born the Mapeley consortium made up of Soros Real Estate Partners, the Ritblat family's Delancey Estates and Fortress, an American investment group. Priest is chief executive.

Mapeley duly triumphed in the auction in August 2000 and in April it will take control of 1.5m sq ft of space comprising 750 offices and housing 90,000 staff.

The price paid was �220m in a deal that could yield as much as �2 billion for Mapeley over the next 20 years.

It also leaved 42-year-old Priest in a strong position to win other outsourcing competitions in the public and private sectors as organisations recognise the need to focus on core activities and let an outsider manage their property assets.

His latest victory was persuading Abbey National to hand over its entire property portfolio to receive the Mapeley treatment. The attraction for Abbey is that the property comes off its balance sheet and in return it is provided with serviced office space.

"Abbey's share price rose when the deal with Mapeley was announced," says Priest. "Investors could see that it was getting out of the dangers of the property market and focusing on its core activity."

Priest's first stab at property outsourcing was a failure. He organised Bank of America's bid to take over the Department of Social Services' 1.6m sq ft of office space in 1998, but he lost out to Trillium, a Goldman Sachs-backed consortium.

Yet the 15 months he spent on his abortive bid convinced him that property outsourcing was an emerging market set to explode.

"Losing the DSS competition was shattering," says Priest. "After 15 months of work and no sleep, we came away with nothing."

But eh experience provided the blueprint for Mapeley, "Companies were starting to ask themselves, 'Why do we own all these assets?' By relinquishing its property portfolio, a company can free up capital, take away risks and uncertainty of the property market and focus on its core business," he says.

At the start of 1999 the government announced the Inland Revenue / Customs and Excise auction and Priest began assembling his bid.

"I thought very hard about the Mapeley model," he says. "I thought it should not just cover property, but technology, facilities management, services - providing an integrated answer for the client."

He first signed up Soros and then locked in Fortress, a leader in asset-backed finance. "It was important that we could differentiate ourselves from the competition," he says. "I knew if we could combine Soros and Fortress we would have a very powerful combination."

This mixture was then leavened with British property expertise through the recruitment of Delancey, whose chief executive is Jamie Ritblat, younger son of the man who built up British Land. "I saw them as very forward thinking and entrepreneurial - a great company to have on board," says Priest. "For every part of our endeavour we wanted to have world-class partners."

Priest and his team worked tirelessly in the months leading up to the auction. "A bid of that size is like a marathon interspersed with a series of sprints," he says. "I now know how junior doctors feel. Everyone on the team was suffering from sleep deprivation."

After the proposals were submitted, everything went quiet for about three weeks. "Those were the worst three weeks of my life," he says. "I just tried to keep myself busy."

The silence ended in August when Mapeley emerged triumphant, beating off both Trillium and Guy Hands' Principal Finance Group Nomura.

There is normally a haggling process after proposals have been submitted, but this did no happen over the Revenue buildings. "There was clearly enough blue water between us and the next bid not to have best and final offers," says Priest. "We threw everything on the table in the first place and it paid off."

He insists that Mapeley is not just a building company. "We will provide businesses with what they need to do business," he says. "We provide property, services and anything that isn't central to that business's core activity."

Priest believes Mapeley will eventually become totally responsible for its clients' working environments, from sourcing caterers or staff facilities, such as a dentist, to finding software and technology solutions.

He says he can bid only for so many contracts at a time. "You have to be completely focused and committed to a bid, otherwise you will lose," he says. "We will never be a company with 150 contracts."

Having abandoned the safety of his banking career, Priest is hoping to make a fortune from his Mapeley stake. "I have let go of the comfort blanket of being a banker," he says. "My interests are aligned with that of the institutional shareholders - we all succeed or fail together."

Priest, who studied law at Christ Church, Oxford, find his job all-consuming, leaving him little time to indulge in his passion for cricket. "Most contract competitions are held in the summer, which means working eight-day weeks," he says. "But I've never had so much fun in a professional environment. I enjoyed being a banker but this is so much more satisfying. Creating a potentially vast business and watching it grow