CKE Restaurants Inc. said Saturday it took the offer, worth $12.55 per share, from Apollo affiliate Columbia Lake Acquisition Holdings Inc.
CKE accepted Thomas H. Lee's offer of $11.05 a share in February. That offer included about $619 million in cash and the assumption of about $309 million in debt. Lee was among a trio of investment firms that bought Dunkin' Brands Inc. in 2006.
CKE and the fast-food industry have been hurting as customers continue to struggle with high unemployment.
The company reported late last month that its fourth-quarter profit grew, but mostly because of a sizable tax benefit.
CKE's revenue fell nearly 5 percent in the quarter, while sales at stores open at least a year dropped 6 percent. This figure is considered a key performance indicator because it measures growth from existing locations rather than newly opened ones.
The company operates and franchises 3,141 restaurants in 42 states.