WASHINGTON -- Presidential candidate Ralph Nader called the advertisements on uniforms during major league baseball's season-opening series an "obscene embarrassment" and sent a letter of protest Tuesday.

"This overcommercialization is sapping the fun out of being a fan of major league baseball," Nader wrote in his letter to commissioner Bud Selig. "Now, you have sunk to a greedy new low."

The ads appeared on the uniform sleeves and caps of the New York Yankees and Tampa Bay Devil Rays during their two-game series in Tokyo on March 30-31.

While the New York Mets and Chicago Cubs wore similar ads when they played in Tokyo in 2000, and baseball said in advance that the Yankees and Devil Rays would wear patches, Nader said the ads this year "ambushed fans across the country and left them shaking their heads at this obscene embarrassment."

Tim Brosnan, baseball's executive vice president for business, has said he is open to considering additional uniform advertising in the future, but Selig and chief operating officer Bob DuPuy have said it is not under consideration.

"We urge that you immediately put this issue to rest once and for all and eliminate any current or future possibility that major league baseball will accept advertisements on uniforms," Nader wrote.