CBS Corp., which has been rapidly snatching up pieces of Internet companies by swapping ad space, said Wednesday that it will broaden its recently announced deal with Hollywood.com to instead acquire an equity stake in parent company Big Entertainment Inc. CBS was to give Hollywood.com $100 million in advertising for a 35 percent stake in the Web site but now will give $105 million in ads over seven years for a 30 percent stake in Big Entertainment, which runs several Web sites including Hollywood.com. Big Entertainment's assets will also soon include CinemaSource and Pkbaseline.com, a film data base. CBS said it will begin advertising Big Entertainment and Hollywood.com on television in the fall, and will also tout the company on its massive billboard assets and radio properties.