Both of baseball's home-run kings will be in the restaurant chain's latest ad campaign, the fast-food company said Thursday.

Big Mac took a bite out of the record book in 1998.

The television ads, featuring the company's Big Mac hamburger, are an attempt to capitalize on this year's stirring home run race. Sosa's spots will begin airing Saturday, and Mark McGwire's next Thursday.

Both have appeared in local McDonald's ads this season -- Sosa in Chicago and McGwire in St. Louis -- but this new campaign is nationwide.

"It just seemed a natural to get these two guys who have basically ignited sports this year," said John Lewicki, the national sports marketing manager for McDonald's. "They are the two most celebrated athletes of the year."

The 30-second spots will be in both English and Spanish. Sosa and McGwire will not appear together in the ads.

McDonald's said the ads were an extension not just of the local commercials but also of the relationship the company established with the two stars' charities.

Ronald McDonald House Charities pledged $61,000 to each player's favorite charity after they broke Roger Maris' home run record of 61, and $10,000 for each home run thereafter.

By season's end, $151,000 was going to the Mark McGwire Foundation for Children and $111,000 to the Sammy Sosa Foundation, which helps underprivileged children in the U.S. and the Dominican Republic.

McGwire finished the season with 70 home runs, and Sosa 66.