Callaway Golf Co., makers of Big Bertha clubs, added pop singer Justin Timberlake to a list of endorsers that includes Phil Mickelson, Annika Sorenstam and Alice Cooper.

Timberlake, a six-time Grammy Award winner whose 2006 song "SexyBack" reached No. 1 in five countries, is an avid golfer and hosted his own U.S. PGA Tour event in Las Vegas this month.

The former lead singer of 1990s band `N Sync, Timberlake will use Callaway clubs and other equipment during charity and celebrity tournaments, Carlsbad, California-based Callaway said in a news release.

"We want to make sure the game of golf continues to appeal to a younger audience," Callaway spokeswoman Michele Szynal said of Timberlake's signing. "He's relevant culturally and he loves golf. He's the real deal."

Timberlake, a 27-year-old native of Memphis, Tennessee, is the first non-golfer to be signed to an endorsement contract by the company, Szynal said. While Cooper, who credits golf with helping him kick drugs and alcohol, has appeared in Callaway advertising, he wasn't an official club endorser, Szynal said. Timberlake won't be used in Callaway advertising.

As a 6-handicap on the golf course, Timberlake has "impressed many with his skills" and established "credibility" within the industry, the company said.

"Golf has become an incredibly important part of my life," Timberlake said in a statement. "There's nothing like hitting the ball perfectly. I'm hooked on that feeling."

Financial terms of the contract weren't disclosed by Callaway.

Callaway stock fell 20 percent on Oct. 15, the most in four years, after the company lowered its 2008 profit and sales forecast because of "turmoil in the global financial markets."

Callaway shares fell nine cents to $10.01 today in New York Stock Exchange composite trading.