The Chicago Cubs failed yesterday in their bid to have the Illinois Supreme Court overturn state and city laws that effectively ban night baseball at Wrigley Field.

The court ruled that the laws banning night events at the 70-year-old National League stadium -- the only major league ballpark without lights -- were reasonable uses of government power.

"It's another nail in the coffin, so to speak, for the Cubs at Wrigley Field," Cubs General Manager Dallas Green said . . .

The Rocky Mountain News reported that the city of San Francisco sent a letter dated Sept. 17 to each National League team threatening legal action if any team votes favorably on a move by the Giants to another city. The message said, in part:

"If the subject of moving the San Francisco Giants comes up at any meetings or agendas and if you vote favorably to allow them to move, we will file a suit for interference of our lease."

On Wednesday, Giants owner Bob Lurie announced plans to buy out his Candlestick Park lease and temporarily share the Oakland Coliseum with the American League A's. San Francisco Mayor Dianne Feinstein said she backs the buyout plan if the county board of supervisors is in favor of it.