Maryland Gov. Harry Hughes said yesterday that although he is "keeping an open mind" at this time he can neither support nor oppose the joint Montgomery-Prince George's proposal to dedicate some sales tax revenues for Metro subsidies in the two counties.

"I will continue to think about it and talk with other people about it to see if there is some solution," the governor said at his weekly press conference, "but it's a rather big complicated problem involving a lot of money."

Hughes took essentially the same position in a private meeting late Wednesday with Montgomery County Executive Charles W. Gilchrist and Prince George's Executive Lawrence J. Hogan, who formulated the bicounty proposal.

It's a very fluid situation," Gilchrist said cautiously yesterday. "We have no reason to be pessimistic."

The two counties' plan, to be introduced as a bill in the legislature today, requires the state to set aside $145 million in sales tax revenues, largely for Metro-related expenses.

Half the total would be divided among all jurisdictions in the same proportion in which they contribute to statewide sales tax income. That would give about $10.8 million to Montgomery and $11.8 million to Prince George's for Metro operating subsidies.

The rest of the sales tax revenues would be sent to the state Transportation Trust Fund, out of which the state would pay for a variety of transportation porjects around the state, including Metro construction costs and half of the two counties' continuing Metro operating subsidies.

Without state help, Montogomery and Prince George's will be forced to find comparable local revenues to meet U.S. Transportation Secretary Brock Adams' decree that local funding must be assured before federal money will be released to complete the 100-mile system.

Prince George's, however, would have great difficulty paying its Metro share out of local revenues because of the passage of TRIM, the tax limitation charter amendment.

Hughes said yesterday that dedicating a portion of sales sax revenues for transportation programs would be a "tremendous change of policy." Hughes added he is reluctant to take a position on the question without extensively examining the issues beforehand.

But the governor added, "I hope I can always keep an open mind to new approaches, new policy changes and I will do that in this case." He has called a meeting of the legislative leadership today to discuss the Metro proposal.

Meanwhile, Gilchrist, a former state senator, has summoned the county's legislative leadership to a breakfast meeting today to formulate Metro strategy.