WASHINGTON — The Federal Communications Commission on Wednesday proposed repealing its blackout rule, which for decades has been the bane of sports fans whose ability to watch their favorite team’s home games on television has depended on whether enough of their fellow fans bought tickets to see it in person.

The rule has prohibited cable and satellite television companies from showing sports games in areas where leagues or individual teams require that the games be sold out before they can be shown on television.

Retracting the rule, which was adopted in 1975, would not necessarily prevent all such blackouts, the F.C.C. said. Separate league blackout policies would remain in place for over-the-air broadcasts, though not for cable and satellite companies. If the repeal passes, the leagues would then have to negotiate with cable and satellite companies to keep those games off the air.

The reasoning behind the blackouts — to protect ticket sales, which accounted for most of team revenue when the rule was applied — has all but disappeared in recent years. Money from sponsorships, merchandise and advertising are now big moneymakers, and sold-out games have become more frequent as city populations have grown. Sports like professional football have boomed in popularity and some teams have moved to smaller stadiums.