Billionaire Warren Buffett’s Berkshire Hathaway Inc. will pay $4.5 billion for a 60% stake in Marmon Holdings Inc., the private company owned by trusts for Chicago’s Pritzker family.

Berkshire will buy the rest of Marmon within six years, the Omaha, Neb.-based company said yesterday in a statement. Marmon’s operating income more than tripled from 2002 to 2007, and the company has annual sales of $7 billion from more than 125 manufacturing and service units.

Mr. Buffett, 77, built Berkshire over four decades, buying out-of-favor stocks and manufacturers to transform a failing textile maker into a $210 billion holding company. Berkshire, which had more than $45 billion in cash as of September 30, is as prepared as it has “ever been” to buy a “big business outright,” he told shareholders at an annual meeting in May.

Marmon has an “impressive record of growth and profitability,” with businesses including wires and cables for energy-related markets and the leasing of construction equipment, Mr. Buffett said in the statement yesterday. “The decision to purchase and work out the details of this transaction was done without delay.”

The acquisition is expected to be completed in the first quarter of 2008, with Berkshire acquiring the remainder of the company at a cost based on future earnings.

The takeover is the largest announced by Mr. Buffett since 2005, when Berkshire’s utility company agreed to buy PacifiCorp from Scottish Power Plc for $5.1 billion in cash and assume $4.3 billion in debt. Mr. Buffett agreed last year to pay $4 billion for 80% of closely held Israeli toolmaker Iscar Metalworking Cos.

Berkshire, which traded at $2,950 on December 31, 1987, is poised to post its 17th annual gain in 20 years. It climbed $3,980 yesterday to $137,980 in New York Stock Exchange composite trading and is up 25% in 2007.

The Pritzker family, which controls Global Hyatt Corp., has discussed breaking up its holdings since the 1999 death of Jay Pritzker, who began the hotel company buying the Hyatt House in Los Angeles in 1957. Their investments range from a global credit-check company to a maker of artificial joints.

Marmon employs 21,500 people, mostly in North America, Britain, Europe, and China, according to the company’s Web site. Its businesses include a dozen companies that manufacture wire and cable products for energy-related and construction uses.

The group also has a transportation services operation that produces railroad cars and leases tank containers in China. The Chicago-based company has units that lease cranes to energy and mining companies and provide water treatment.

Marmon was acquired in 1953 by Jay Pritzker and his brother Robert, according to the statement.

Berkshire spokeswoman Jackie Wilson and the chief financial officer, Marc Hamburg, didn’t return calls seeking comment. A spokesman for Marmon, David Dees, had no immediate comment.