The most-watched network will carry up to eight fights this year, with more events possible on CBS Sports Network.

For the first time in 15 years, CBS will return regular live boxing its schedule. Premiere Boxing Champions will kick off on Saturday, April 4, with light heavyweight world champion Adonis Stevenson defending his WBC title against Sakio Bika, the former super middleweight champion from Australia. The network will carry up to eight fights in 2015, with others possible on CBS Sports Network.

The CBS events will be promoted during Showtime's long-running Championship Boxing series; Showtime's March 28 doubleheader featuring Jhonny Gonzalez and Gary Russell Jr., and Jermell Charlo and Vanes Martirosyan, will preview the April 4 debut of CBS' Premiere Boxing Champions.

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Shoulder programming will air on CBS, Showtime and CBS Sports Network, while a significant marketing budget has been earmarked to promote the fights on CBS.

The venture will culminate in the May 2 Showtime PPV presentation of Floyd Mayweather against an opponent who has yet to be determined. Manny Pacquiao is Mayweather's anticipated opponent, but so far the two sides have yet to settle on a contract for what could be the next PPV blockbuster.

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CBS Corp. president and CEO Leslie Moonves has been a proponent of bringing boxing back to CBS; the last time the sport aired on CBS regularly was in the late 1990s. The initiative gives CBS more live sports programing at a time when sports is about the only DVR-proof genre left on broadcast television. And robust cross-promotional efforts on CBS, the most-watched TV network, could potentially bring a new audience to Showtime's signature Championship Boxing series.

Mayweather has proven to be a big draw for Showtime; his September 2013 fight against Canelo Alvarez generated 2.2 million PPV buys on the network, grossing a record $150 million, with total fight revenues closer to $200 million, including sponsorships, international TV rights and a blockbuster $20 million gate.