Hardee's and Carl's Jr. Swallowed Up by Thomas H. Lee Partners

CKE Restaurants (CKE), owner of the Carl's Jr. and Hardee's chains, agreed on Friday to sell itself to buyout firm Thomas H. Lee Partners for $928 million, underscoring the economic power of fast-food restaurants during tough economic times.

The deal values CKE shares at $11.05 in cash, representing a 24% premium over Thursday's closing price, and includes the assumption of $309 million of net debt. Shares of CKE, based inCarpinteria, Calif., soared in pre-market trading, They have gained 28% over the past year. CKE has 3,100 company-owned and franchised eateries across the country.

Having Thomas Lee as a corporate parent will help CKE better compete against rivals including McDonald's (MCD) and Burger King (BKC), which have gained market share as diners bypassed pricier casual-dining chains. In January, CKE posted a 6.4% decline in same-store sales (stores open more than one year), citing bad weather and continued high unemployment.

More Heat in the Kitchen

Boston-based Thomas H. Lee is no stranger to the food business: The firm and several partners acquired Aramark, which provides meal service to corporate cafeterias, colleges and universities, and sports stadiums, for $8.3 billion in 2006. It's also one of three co-owners of Dunkin' Brands, parent of Dunkin' Donuts and Baskin-Robbins.

Other fast-food chains are bound to feel the heat from the sale. While McDonald's fourth-quarter results showed an earnings rise of 23% year-over-year, Yum! Brands (YUM), owner of KFC, recently reported disappointing fourth-quarter results. And Wendy's/Arby's Group (WEN) shares are down 2.25% over the past year.

Given the premium CKE fetched, investors are going to pressure other fast-food operators to get them a return as good or better.