Blackstone Group LP is raising $12.5 billion from investors to start the world’s largest takeover fund as corporate buyouts set a record pace.

Blackstone has commitments of $11 billion, plus $1.5 billion for a supplemental fund, according to a New Jersey state pension fund document and a person familiar with the New York-based firm. The company, co-founded by Peter Peterson and Stephen Schwarzman, last raised $6.45 billion in 2002.

The new fund eclipses Goldman Sachs Group Incorporated’s $8.5 billion offering and the $7.85 billion the Carlyle Group raised. Buyout firms, which finance corporate takeovers mostly with borrowed money, disclosed $148 billion of acquisitions during the first half of 2005, almost 65% more than in 2004, data compiled by Bloomberg show.

“These very large firms are able to take on much bigger companies than they could before,” a managing partner of Electra Partners Europe LLP, Nigel McConnell, said. Electra closed a $1.5 billion fund yesterday. “There’s a huge amount of capital available,” Mr. Mc-Connell said.

A spokesman for Blackstone, John Ford, declined to comment.

Blackstone took about three months to line up investors.

Carlyle raised its most recent fund in March after about six and a half months.

Buyout firms are seeking $200 billion this year for new funds, according to Private Equity Intelligence Limited in London. That would top the high of $177 billion in 2000, a partner in the New York office of Ernst & Young LLP, John O’Neill, said. Ernst & Young has tracked buyout fund-raising since 1994.

Blackstone has made more than $80 billion of acquisitions since it was started in 1985 by Messrs. Peterson and Schwarzman. By comparison, Kohlberg Kravis Roberts & Company, which was founded in 1976 by cousins Henry Kravis, George Roberts, and Jerome Kohlberg, has completed more than 120 deals valued at more than $136 billion.

KKR and Blackstone are among seven firms purchasing SunGard Data Systems Incorporated, whose software handles most Nasdaq Stock Market trades, for $11 billion in the biggest leveraged buyout since 1989 when KKR acquired RJR Nabisco Incorporated for $31 billion. Blackstone is also acquiring the Legoland theme parks from Denmark’s Lego A/S for $457 million.

Blackstone agreed in June to buy Wyndham International Incorporated, a Dallas-based owner of hotels and resorts, for $1.44 billion in cash, its latest purchase in the lodging industry. The company last year bought Extended Stay America Incorporated for $3.1 billion and Prime Hospitality Corporation for $762 million.

The SunGuard deal helped the buyout industry increase its share of the $1.3 trillion global mergers market by 15% this year, to 11%, Bloomberg data show. Buyouts are booming, with stock markets down more than 20% from the 2000 peak, and borrowing costs are almost half what they were a decade ago.

Buyout funds returned 16% in 2004, according to Thomson Venture Economics and the National Venture Capital Association. That compared with a gain of 9% for the Standard & Poor’s 500 Index, and 8.3% for the Hennessee Hedge Fund Index, compiled by Hennessee Group LLC in New York.

New Jersey’s State Investment Council, the 10th largest American state pension fund with $70 billion under management, agreed Thursday to invest $100 million in Blackstone’s new fund, Blackstone Capital Partners V LP, according to a pension fund document. New Jersey has committed $1.75 billion this year to buyout funds as part of an effort by the state investment council chairman, Orin Kramer, to diversify assets and improve returns.