In a preliminary ruling yesterday, a state judge upheld a new ethics law passed by the Maryland General Assembly in April, which requires that a member of the Prince George's County Board of License Commissioners resign his position if he wants to run for elective office.

The commissioner, Robert S. Miller of New Carrollton, filed candidacy papers in March in preparation for a bid for the Maryland House of Delegates in September. Miller, 51, an advertising agent for The Washington Post, is one of three members of the county's Board of License Commissioners, which regulates the sale of liquor in the county and issues licenses for establishments that sell liquor.

In April, the Maryland General Assembly passed a law amending the ethics code for commissioners. It stiffened conflict-of-interest laws and added the proscription against commissioners running for office. Miller initiated the first challenge of the new law, arguing that it violated his constitutional rights to equal protection and freedom of expression by singling out liquor board commissioners for special treatment. The state's attorney's office defended the law, saying that its limitations are justified because the commissioners' "unique and broad powers over a very heavily regulated business" offer "great potential for abusing this power for political purposes."

State Circuit Court Judge Perry G. Bowen Jr. said from the bench that he believed the state law is constitutional. He said that he would wait to issue a final ruling until June 30, when the U.S. Supreme Court is expected to rule on a similar case from Texas.

Miller said he would appeal or withdraw his candidacy rather than resign the $10,000 position, one of the last and most powerful patronage positions in the county. "I think they're interfering with my constitutional right to run," said Miller, who added that the new code is "a good bill, until you get down to the last part."

The bill was introduced by state Del. Charles Blumenthal (D-Prince George's) in response, he said, to a series of articles in The Washington Post that described how one liquor board commissioner, Gerard Holcomb, allegedly held a hidden interest in a restaurant regulated by the board. The matter is under investigation by the county state's attorney's office. The "resign-to-run" amendment was added by state Sen. Thomas V. Miller.