While it's been rumored for some time, a deal between Nike and Jennifer Aniston appears to be on the verge of signature.

The deal, sources say, may be the largest sum ever paid by the sportswear company for a celebrity endorsement. The campaign is said to be international in scope and will, perhaps, include a Super Bowl 2007 spot.

While Aniston may be paid a fortune for this deal, she says she will donate a large sum of it to Cancer charities of her choice.

Jennifer Aniston was spotted leaving a Santa Monica recording studio August 29. The former 'Friends' star was taping voiceovers for upcoming commercials which will focus on cancer research.(photo source:fadeyouth)