The Federal Communications Commission on Wednesday said that when the conversion to digital service becomes mandatory in 2009, satellite TV providers essentially cannot pick and choose which high-definition signals they may carry.

The FCC said if El Segundo-based DirecTV Group Inc. and its rival, Englewood, Colo.-based Dish Network Corp., carry a high-definition signal of one local broadcaster they must carry all HD signals in the market. The companies can apply for waivers where the requirements would strain satellite capacity.

The mandate comes the same week as a launch to put one of DirecTV’s HD satellites in orbit is scheduled. The satellite was to launch Monday by Long Beach-based Sea Launch, but was postponed until today. DirecTV said that its plans for HD rollout are still on schedule despite the setback.

Once operational, the new satellite (DirecTV 11) will expand the satellite TV provider’s capacity to 150 national HD channels and 1,500 local high-def channels. DirecTV’s current satellite fleet has a capacity of roughly 100 national HD channels.

DirecTV did not immediately return calls for comment.

Shares in DirecTV were down 1 percent to $24.96 in early trading Wednesday.