(Reuters) - Major League Baseball (MLB) will open its season in Tokyo, Japan, for the first time in four years when the Seattle Mariners and Oakland Athletics hold a two-game set to start the 2012 campaign, the league said on Wednesday.

The series, set for March 28-29 at the Tokyo Dome, marks MLB's fourth season-opening trip to Japan and first since the Boston Red Sox and Athletics played in 2008.

MLB said the games are being held in Japan to help assist with the rebuilding efforts in Japan following the devastating earthquake and tsunami earlier this year that left thousands dead and billions of dollars in damage.

"Opening Series 2012 will be an excellent opportunity to bring the game of baseball to fans across the globe and to celebrate the many contributions to the game by Japanese players," MLB Commissioner Bud Selig said in a statement.

"Most importantly, with the shared love of baseball between our nations, I believe that we can use this event to further assist the ongoing relief efforts throughout Japan."

Over 875,000 fans have attended 21 MLB opening games in Monterrey, Mexico (1999), Tokyo (2000, 2004, 2008) and San Juan, Puerto Rico (2001), according to MLB

The two games in Japan next year are expected to draw sellout crowds, with the Mariners and their hugely-popular Japanese outfielder Ichiro Suzuki returning home.

Japanese slugger Hideki Matsui, who will be a free agent at the end of the 2011 MLB season, could re-sign with Oakland.

(Writing by Steve Keating in Toronto; Editing by Frank Pingue)