ANNAPOLIS, DEC. 18 -- Maryland Gov. William Donald Schaefer announced plans today to build a $290 million light rail system connecting Anne Arundel and Baltimore counties to a terminal beside the two planned sports stadiums in downtown Baltimore.

The 27-mile system could begin operations by 1991 if the legislature approves part of the funding, Schaefer and other state officials said today. The plan could run into trouble, however, from Washington area legislators who also want a light rail system for their areas.

Schaefer immediately tried to quell expected complaints that the rail line would serve only the Baltimore area. Schaefer was mayor of Baltimore and has been accused of giving that area special attention since becoming governor.

"You've got to have a start," said Schaefer, who donned a railroad conductor's cap at one point during today's news conference. "You can't do all things at one time. You can be sure this will be moving along. This is the beginning."

Senate President Thomas V. Mike Miller Jr. (D-Prince George's) and House Appropriations Committee Chairman Charles J. Ryan (D-Prince George's) called the light rail attractive but said the state also must seriously study light rail for the Washington suburbs.

"Our expensive Metro system in the Washington area is fine, but it only takes us out as far as the Beltway," Ryan said. "It would seem a natural extention to have light rail running in this area."

Miller predicted that the light rail proposal will be controversial "because these are monies coming out of a common pot" but serving only one part of the state. "All of us want to be statesmen, but we have constituencies in our districts," he said. Miller also said legislators will be concerned about the cost, about $70 million more than the expected cost of the planned Baltimore baseball and football stadiums.

The system would connect Baltimore, Baltimore-Washington International Airport and the north Anne Arundel County commercial hub of Glen Burnie. One stop would be Camden Yards in Baltimore, the site of the planned sports complex. The state also will study extending the line to Annapolis.

The system, called light rail because its cars are more like trolleys than heavier trains and subways, could travel up to 55 mph but also run along city streets like streetcars. From one to four cars long, they would be powered by overhead electric cables and pick up passengers at stations that look like bus stops.

Officials said that after the first two years of operation, the system would carry 34,000 passengers daily.

Schaefer said the light rail system can be paid for largely from the state's gasoline tax, which he said is bringing in about $100 million more each year than expected, without affecting any of the other $5 billion transportation projects planned in Maryland by 1993. In addition, he said, the state will ask Baltimore, Baltimore County and Anne Arundel to pay $15 million each and will seek federal funding.

He said he will ask the state legislature to approve $43 million for the project during the coming session. Legislative approval is needed to add light rail to the list of approved projects on which state transportation funds may be spent and to amend another law that requires that federal funds be used to pay two-thirds of the cost of all mass transit projects.

Anne Arundel County Executive James Lighthizer, Baltimore County Executive Dennis F. Rasmussen and Baltimore Mayor Kurt L. Schmoke endorsed the proposal today.