NBC and ESPN declined to match Fox's offer for their postseason packages by Tuesday's deadline.
Major league baseball planned to announce the deals Wednesday, a baseball official said on the condition he not be identified.
"We have notified major league baseball that we have passed on their offer and we wish them well going forward," NBC Sports president Ken Schanzer said Wednesday (Tuesday EDT) from Sydney, Australia.
ESPN spokesman Mike Soltys would not comment on whether the cable channel decided to keep its playoffs rights. ESPN is owned by The Walt Disney Co., as is ABC.
A baseball official, speaking on the condition he not be identified, confirmed ESPN passed, saying the decision was partly based on price and partly because ABC wasn't interested in the network package.
ESPN began an $800 million, six-year regular season contract this season, with about $40 million attributed to this year.
With the new Fox contract averaging about $417 million, and the remainder of the ESPN contract averaging $152 million, the two deals give baseball an average of about $570 million per season, or $19 million for each of the 30 teams.
Baseball scheduled a telephone conference call of its executive council for Wednesday to discuss the deals before they are announced publicly at 1 p.m. EDT, an baseball official said.
NBC will lose baseball for the second time in 12 years. It broadcast the sport from 1947 through 1989, often as baseball's sole national network, then renewed the relationship in 1994.
That $570 million figure represents an increase of 50 percent from the $380 million per season baseball averaged the past five years from its contracts with ESPN and its five-year deals with Fox and NBC, which expire after the World Series.
Fox's $2.5 billion outlay, which would also cover an extension of current deals for regular-season games on Fox and its outlets, was confirmed by three TV and baseball sources.