Sean McManus, president of CBS News and Sports, said the annual payments of $700 million over the last three years of the original deal would have been a load for the network.
"As a practical matter, to generate the kind of revenue and exposure that was needed to complete this deal ... we needed a cable partner and needed the assets of Turner to make this package complete for CBS,” he said.
CBS and Turner Sports also will coordinate production of the games to provide consistent telecasts. McManus said the coverage will continue to include "look-ins” of other games.
The NCAA tournament is the latest sports brand Turner has added to its growing sports portfolio, which includes the NBA, WNBA and a baseball package that includes TV rights to the first round of the playoffs and one of the two league championships.
The Turner networks have large viewership bases. TBS is available in 100.4 million homes, TNT 99.4 million and truTV 92.4 million. CBS reaches 114.5 million homes.