Advent agrees to buy Ares’ AOT, maker of Serta mattresses

By Bloomberg News

Advent International Corp., the Boston-based leveraged buyout firm founded by Peter Brooke, agreed to buy a majority stake in AOT Bedding Super Holdings, the maker of Serta and Simmons mattresses.

The transaction values the mattress company at about $3 billion including debt, said a person with knowledge of the matter. The purchase is expected to be completed in the fourth quarter, Advent said in a statement sent by e-mail that didn’t disclose terms.

Existing investors Ares Management LLC, based in Los Angeles, and the Ontario Teachers’ Pension Plan will retain a “significant” stake in AOT Bedding, the private equity firm said in an e-mailed statement. Chuck Dohrenwend, a spokesman for Advent International, declined to specify the size of its stake or comment beyond the press release.

Competitors include Tempur-Pedic International Inc., a pioneer of memory-foam mattresses that last year became the biggest publicly traded mattress company by revenue as sales rose 28 percent to $1.42 billion. Sealy Corp., a 131-year-old company and user of coil-spring technology, fell to No. 2 with sales of $1.23 billion, little changed from 2010.

Serta, in a June 11 statement on its website, said it had become the “No. 1 mattress company in the US” for the first time after an 18 percent sales increase in 2011, without specifying whether that was based on volume or dollar sales.