Apprentice star Sir Alan Sugar is stepping down as chairman from Amstrad, the electronics company he founded in 1968.
Sir Alan said he is quitting after his company was acquired by Sky last year in a £125 million deal.
However, he is not retiring yet and the 61-year-old will remain involved in his other ventures, which include Amshold, Amsprop, Amsair and Viglen computers.
He will also be back on television next year for a fifth series of The Apprentice.
Last week, he also refused to rule himself out as a possible candidate for the next London mayoral election, due to be held in 2012.
Sir Alan said: "This is a move that has been planned for a while and it's the right time for me to step down from my role at Amstrad.
"The past 40 years have seen Amstrad grow from a start-up business to the success story that it is today, which is credit to the talented and loyal team here."
Entrepreneur Sir Alan, the son of an East End tailor, left school at the age of 16 and founded Amstrad, which stands for Alan Michael Sugar Trading.
His firm was an early manufacturer of personal computers and was first listed on the London Stock Exchange in 1980.
By 2007, Amstrad was developing set-top boxes for BSkyB, which then bought out the company.
Sir Alan has achieved a net worth of £830 million and was ranked 92nd in the 2008 Sunday Times Rich List.