Updated from Wednesday, Oct. 14

NEW YORK ( TheStreet) -- Lazard ( LAZ - Get Report) CEO Bruce Wasserstein, who the company said on Sunday was hospitalized with an irregular heartbeat, has died.

Wasserstein, 61, became a Lazard director in 2002 and was named CEO after ushering the company public in 2005.

Lazard CEO Bruce Wasserstein

Most recently, he was reported to have been advising Kraft Foods ( KFT) on its takeover attempt for candy maker Cadbury ( CBY).

Steven Golub, vice chairman of Lazard, has been named interim CEO, effective immediately, the company said in a statement.

A former Harvard-trained lawyer, Wasserstein cut his investment banking teeth during the high-flying dealmaking LBO days of the 1980s with both First Boston and his own shop -- Wasserstein Perella Group -- which he founded with Wall Street veteran Joseph Perella.

He was known for working on some of the most groundbreaking deals of that era, including KKR's takeover of RJR Nabisco. Along with a cadre of investment bankers of that time, perfected the art of what eventually became known as the hostile takeover. Wasserstein later worked on the merger between AOL and Time Warner, one of the biggest calamities in merger history.

Wasserstein was CEO of Wasserstein Perella between 1988 and 2001 before selling it to Germany's Dresdner Bank AG for about $1.4 billion.

Forbes magazine estimated Wasserstein's net worth at $2 billion.

Aside from his work at Lazard, Wasserstein served as chairman of Wasserstein & Co., a private investment firm. Wasserstein & Co. targets investments between $30 million and $150 million. It has investments in companies ranging from Penton Media Inc., a publisher of trade magazines, to gourmet food seller Harry & David.

-- Written by Sung Moss in New York

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