By Marc Jones

LONDON (Reuters) - Even the most successful investors can get it horribly wrong, as reclusive British tycoon Joe Lewis has just found out.

The septuagenarian British billionaire currency trader last year built a stake approaching 10 percent in Bear Stearns, a U.S. investment bank weakened by the subprime crisis and widely seen as a takeover target.

The speculation was half right. JP Morgan set a deal to buy the stricken bank over the weekend, but at a knockdown $2 a share, implying a loss for Lewis of more than $1 billion (500 million pounds).

Lewis on Monday called the takeover offer "derisory", according to U.S. business news channel CNBC, and said he does not expect JP Morgan to be successful in closing the deal.

The reclusive financier, who dropped out of school aged 15 to work in his father's pub in London's East End, is one of Britain's richest men.

He made most of his estimated fortune of over $5 billion from foreign exchange bets that shook some of the world biggest currencies.

An avid golfer and a shareholder in London soccer club Tottenham Hotspur, Lewis counts golf professionals Ernie Els and Tiger Woods as business partners. Actor Sean Connery is a friend and neighbour in his Bahamas resort.

Lewis, who generally prefers to stay out of the limelight, grabbed headlines last year after building the biggest individual-owned stake in Bear Stearns, the U.S's fifth-biggest investment bank.