Houston Astros owner John McMullen has had informal contact with the D.C. Baseball Commission about the possibility of moving his team to Washington for the 1987 season, the chairman of the commission said yesterday.

City Councilman Frank Smith, who heads the commission, wouldn't reveal whom McMullen had spoken to, but he said he is convinced that McMullen is serious about relocating the Astros in Washington.

"I think we have to get ready," Smith said. "We've already let him know we're interested. We have agents here that have been talking. I'm not satisfied that we know enough right now, but I think he's seriously considering it.

"I don't want to get excited right now, but it's hard not to be. We don't have a deal yet, and I think he'd really rather stay in Houston if he can make his kind of deal."

Sources in Houston said yesterday they believe McMullen wants to move the Astros to Washington or to sell them to a group in Houston.

"Either way, it works out well for him," said a former business associate of McMullen's.

McMullen could not be reached for comment yesterday, but twice in the past 10 days he said he was very upset about the Astros' declining attendance. He has apparently lost more than $10 million the last two seasons.

Smith said he was "embarrassed" that the RFK Stadium title hadn't yet been transferred from the Department of the Interior to the District, which prevents the District from negotiating a lease. Further, until the lease is transferred, the District won't begin a $13 million renovation project that would get the stadium ready for baseball, Smith said.

"Right now, we're not in very good shape to talk about a lease at RFK," Smith said. "If the title were transferred, I'd be talking to [McMullen] myself."

Transfer of the title passed the House of Representatives and a Senate committee but was blocked from passage by Sen. Mark Hatfield (R-Ore.). Staff people from Hatfield's office and the D.C. Baseball Commission have had discussions about removing his block, which stems from the Audubon Society's belief that the federal government should not give away any more park land.