Roger Werner, who solidified ESPN's dominant role in cable television by acquiring rights to major league baseball games and retaining the network's contract with the National Football League, quit yesterday as president and chief executive officer.

Werner, 40, will become president and chief executive officer of Prime Ventures Inc., a new company being formed by Bill Daniels, who has interests in several regional cable networks.

No successor was named by ESPN, an 11-year-old venture that took one of the first major steps into cable television. The network, which has 56 million subscribers, is 80 percent owned by Capital Cities-ABC and 20 percent by RJR Nabisco.

ESPN officials denied losses in the baseball package were the reason for Werner's departure. The network said it will lose between $30 million and $40 million this year after projecting a $31 million loss.

"We were upfront anticipating losses on baseball," Werner said. "There are no surprises on the baseball losses. That is not a factor in my decision to leave." . . .

Women athletes don't get their fair share of television time and the coverage of them is sexist, according to a study released by the Amateur Athletic Foundation of Los Angeles.

The study found that only 5 percent of television sports news on a sample station was devoted to women athletes, that females frequently were called "girls" instead of "women" and that men's telecasts use more high-tech equipment and statistics.