Major League Baseball will announce tomorrow that Fox, beginning next season, will become its exclusive over-the-air national network for the next six seasons.

Fox’s new, $2.5 billion deal will also provide it and its cable entity Fox Sports Net with all the attractive trimmings, including all playoff games, the World Series and the All-Star Game.

Yesterday, as expected, NBC passed on the opportunity to remain an MLB broadcaster. It had been sharing the postseason with Fox. ESPN also declined to renew postseason rights, although it will remain a regular-season national cable broadcaster of MLB games.