Satellite TV provider Dish Network Corp. urged the Federal Communications Commission to reject cable giant Comcast Corp.'s proposed acquisition of Time Warner Cable Inc., saying the merger would harm competition, according to a regulatory filing.

Dish Chairman Charlie Ergen met with FCC Chairman Tom Wheeler on Monday and made his case against the $45 billion deal, which would unite the nation's two largest cable companies. Among other things, Dish said, the merger "should be denied" because it would give the combined...