The Carlyle Group is among the final bidders for the Dunkin' Donuts and Baskin-Robbins restaurant chains, in what would be the first U.S. consumer retail investment for a company built around its expertise in defense, aerospace and telecommunications.

Carlyle has been eyeing Dunkin' Brands Inc. since this summer and has joined with Thomas H. Lee Partners LP and Bain Capital LLC, both of Boston, to submit a bid for the French-owned food chains, according to two sources familiar with the bid who spoke on condition of anonymity because the bidding process is supposed to remain private.

Groups headed by Kohlberg Kravis Roberts & Co. and by J.P. Morgan Partners have also made bids for the company, which is expected to draw a price of about $2 billion, the sources said.

The auction for Dunkin' Brands comes at the end of a record-setting year for private equity deals.

In the first three quarters of the year, more than 200 private partnerships had raised more than $100 billion to buy companies, eclipsing the previous year-long record of $65.4 billion, set in 2004, according to Buyouts magazine. Washington-based Carlyle and New York's Blackstone Group LP each raised more than $10 billion in buyout funds this year. Investors in the funds include pensions, endowments and wealthy individuals.

The year also saw some of the largest individual deals since 1989's $25 billion buyout of RJR Nabisco. A group of private equity firms bought SunGard Data Systems Inc. for $11.3 billion, Toys R Us was bought out for $8.8 billion in cash and debt, and Carlyle was part of a group that bought car renter Hertz Corp. for $15 billion in cash and debt. Those deals are funded largely by bank borrowing, with the private equity firms putting up 5 to 20 percent of the purchase price in cash. Typically, the target companies are sold within a few years, either to another corporate buyer or in an initial public stock offering.

With the vast amount of cash private equity firms have to put to work, and the economy growing steadily, most experts don't expect the pace or the size of acquisitions to decline next year, either.

"I don't see deal activity slowing down measurably," said Louis J. Bevilacqua, head of the mergers and acquisitions practice at Cadwalader, Wickersham & Taft LLP in New York.

French beverage company Pernod Ricard SA has been soliciting offers for the Massachusetts-based Dunkin' Brands for two months, after acquiring the food company in a larger merger and concluding that it was not a good strategic fit.

Dunkin' Brands, which had worldwide sales of $4.8 billion last year, has three restaurant brands with a combined 12,000 company-owned and franchised restaurants in the United States and elsewhere. Along with Dunkin' Donuts and Baskin-Robbins, it also owns the Togo's sandwich chain.

Carlyle's interest in the well-known consumer chain stems from its hiring in May of Sandra J. Horbach, a 15-year veteran of the buyout industry at Forstmann Little & Co. with an expertise in consumer companies. Carlyle established a consumer team in New York for her to head. At Forstmann, Horbach oversaw some of that firm's most successful consumer company buyouts in the 1990s, such as golf-club-shaft manufacturer Aldila Inc., specialty gift maker Department 56 and mall chain Yankee Candle Co. Though it owns a small department store chain in China, Carlyle has never invested in a U.S. retailer.

A spokesman for Carlyle, which employs 300 in the District, said the firm had no comment. Spokesmen for Kohlberg and J.P. Morgan Partners also declined to comment. J.P. Morgan Partners is the buyout arm of financial behemoth J.P. Morgan Chase & Co., whose investment banking division is actually conducting the sale for the chains' French parent company. The sources said J.P. Morgan Partners came into the bidding recently.

Dunkin' Donuts' parent company is trying to sell the chain and its corporate siblings, Baskin-Robbins and Togo's, for about $2 billion, sources say.