Japan's Daikin Industries Ltd , the world's second-largest maker of air conditioners, has agreed to buy U.S. rival Goodman Global Inc from private equity firm Hellman & Friedman in a deal worth about 300 billion yen ($3.82 billion), according to a source familiar with the matter.

San Francisco-based Hellman & Friedman bought Goodman Global in October 2007 for $1.8 billion in cash, including $1.1 billion of its own capital. The transaction also included assumed debt and other financing for a total of $2.65 billion.

Hellman & Friedman did not respond to requests for comment. Daikin could not immediately be reached for comment.