It's every entrepreneur's dream to build a business out of nothing and make a fortune by selling it or floating it on the stock market. But what do you do if the new owners make a mess of it?

John de Mol, the man behind hit TV show Big Brother, last week became the latest in a long line of businessmen to look at buying back a company he helped to found, in this case Dutch TV production firm Endemol.

In the past few months in the UK, founders of computer services firm Computacenter and of software group Misys have held talks about taking their firms' private.

And newspaper reports say Gerald Ratner - who nearly destroyed his family's jewelry empire by describing one of its products as total crap - is keen to buy back the H Samuel chain of that business from current owner Signet.

The story is similar elsewhere, as founders take advantage of cheap borrowing costs to take back control of companies.

Champagne house Taittinger may return to the founding family as current owner Starwood Capital looks to sell, while the founders of U.S. communications firm Inter-Tel and U.S. oil and gas pipeline operator Kinder Morgan are also involved in plans to take over the businesses.

There are no reliable figures on how much founders spend on buying back companies each year. But the Center for Management Buyout Research says management buy-outs and buy-ins - the most common takeover route for founders - accounted for 49 percent of all UK domestic mergers and acquisitions last year, or about 24.2 billion pounds ($44.6 billion).

MISSING THE BABY

David Storey, director of Britain's Center for Small and Medium Sized Enterprises, believes there are two driving forces behind founders' attempts to buy back companies they have sold.

Firstly, they're missing their baby. And secondly, they see the opportunity for a financial killing.

Having spent time, money and effort in building up a business, entrepreneurs can find it difficult to let go, particularly if they don't agree with the strategy of new owners and they haven't found similar success with other ventures.

Tim Waterstone, who invested redundancy money and 10,000 pounds from his then father-in-law to open his first bookshop, has made six attempts to buy back the book chain that bears his name, having become a vocal critic of successive owners.

But Gordon Gemmill, a specialist in behavioral finance at Warwick Business School, warns against concluding that founders are just acting on sentiment when they buy back businesses.

There is unlikely, particularly if they have retained an interest in the business, to be anyone who knows more about it than them, or anyone who could see a better opportunity for when it is undervalued, he said.

This could explain why shareholders are often suspicious of bids from founders, and why they often fail.

Alan Sugar, one of Britain's best-known businessmen, was blocked by shareholders in 1992 from taking private the Amstrad

electronics business he founded, while minority investors in fashion chain Monsoon have seen off repeated attempts by founder Peter Simon to buy them out.

ALWAYS ONE BUYER

Entrepreneurs adopt a number of strategies to maintain an influence on their businesses, apart from owning them outright.

Richard Branson, who took his Virgin empire private in 1988 after less than two years on the stock market, has since sold off individual companies, sometimes maintaining a stake but almost always insisting the new owner retains the Virgin brand.

Others, like Rupert Murdoch with pay-TV firm BSkyB and Lakshmi Mittal with Mittal Steel, have found leading roles for their children in the businesses they helped to build.

But this is no guarantee of enduring influence.

In one unusual variation on the theme in 2003, Tony K Pidgley made a brief attempt to take over property firm Berkeley

from its founder - and his father - Tony W Pidgley.

For investors, there are mixed feelings about holding shares in a company in which the founder plays a high-profile role.

The downside is the founder might seek to wield more influence than is warranted, or might clash with management.

You have to look on a case-by-case basis, but I'm generally wary of investing if someone owns what is effectively a controlling stake, said Colin Morton at Rensburg Fund Managers.

On the upside, though, investors may feel that if everything goes wrong, there may be at least one buyer for their shares.

United kingdom Software