In what could be the first of a number of major pro football rights pacts, ESPN has extended its rights deal for “Monday Night Football” for eight years, through the 2021 season.

Though the extension of its 17-game-per-season package doesn’t go into effect until the 2014 season, ESPN will begin expanding its NFL studio coverage immediately, with plans for more than 500 hours per year. New programs will be created to complement such existing fare as “Sunday NFL Countdown,” which itself is expanding from two hours to three beginning this weekend.

The deal is believed to be worth $1.9 billion annually, compared to $1.1 billion – $1.2 billion for the previous arrangement, but Credit Suisse said the increase was in line with expectations, in a television world that relies more and more on live event programming.

Implicit in this is ESPN’s potential for passing on some of the costs to its cable and satellite customers.

Like ESPN’s previous deal with the NFL, the current pro football rights deals for CBS, Fox and NBC run through 2013 — but with the sport’s recent labor scare in its rear-view mirror, contract extensions could soon follow with those networks.

“Monday Night Football,” which averaged 14.7 million viewers last year, ranked second among all regular primetime series in male demos and fourth among adults 18-49.

“Today, we’ve secured cable’s most valuable television franchise, along with an enhanced international package of year-round multimedia rights,” ESPN/ABC Sports prexy George Bodenheimer said. “It will help grow our business well into the next decade. No one has the breadth of worldwide media assets or the ability to monetize a property the way ESPN can, particularly with ‘Monday Night Football’ and our complete NFL coverage.”

The extension also covers the Pro Bowl and the NFL draft and includes numerous multiplatform options, as well as international rights to the Super Bowl in 144 countries.

ESPN will launch year-round weekly hourlong show “NFL 32” on Tuesday and Friday companion program “NFL Kickoff” on Sept. 16, while the existing “NFL Live” expands from 30 minutes to one hour.

“MNF” will celebrate its 50th anniversary season in 2020. ESPN began televising primetime NFL games in 1987.