Major League Baseball will get $6.8 billion from News Corp. (NWSA)’s Fox and Time Warner Inc. (TWX)’s Turner networks for the rights to broadcast games through 2021 in a contract extension, said two executives familiar with the deal.

Fox will pay an average of $525 million a year, with Turner paying about $325 million annually, said the people, who asked not to be identified because the terms weren’t made public. The parties announced the deal today without disclosing the financial arrangements.

The deal brings MLB’s total revenue from nationally televised games to $12.4 billion over the next eight years, including an August agreement with Walt Disney Co. (DIS)’s ESPN, Commissioner Bud Selig said on a conference call today.

“We are living in the golden age of baseball,” he said. “I am thrilled that we will continue our relationships with both Fox and Turner.”

The new agreement covers the 2014 through 2021 baseball seasons, according to the statement. Turner’s TBS network and Fox will each have rights to one league championship series in every year and two division series. Fox has rights to more regular-season baseball games, as well as the World Series. Both Turner and Fox will be able to stream games over the Internet live as part of the extended agreement for viewers who already pay for a cable or satellite service.

Sports programming commands some of the highest fees from cable and satellite providers, accounting for a big piece of networks’ revenue. ESPN, for example, generates $5.13 for every pay-TV subscriber, compared with the industry average of 26 cents, according to SNL Kagan.

“This new agreement adds considerable value to our portfolio of offerings,” David Levy, Turner’s president for sports, said in the statement. “We’re pleased to extend our relationship with the MLB brand across multiple screens to create an even richer baseball experience for our viewers, advertisers and distribution partners.”