Three Northern Virginia state senators tried today to persuade Gov. John N. Dalton to withdraw his opposition to a proposed sales tax increase to finance Metro transit operations, but came away without promises.

"He did not close the door completely, but he made it clear he opposes the bill now," Sen. Wiley F. Mitchell Jr. (R-Alexandria) said after the meeting.

"I interpreted his statements to mean that despite his opposition, if the bill passes, he will listen to arguments from our side."

Mitchell, Sen. Omer L. Hirst (D-Fairfax) and Sen. Edward M. Holland (D-Arlington) met with Dalton a day after the governor appeared to threaten a veto of the bill authorizing a penny increase in the sales tax in Northern Virginia.

"He stressed that he never said he would veto this or any other bill that he has not seen in the form passed by the Assembly," Mitchell said, but his assurance failed to leave the Northern Virginians feeling optimistic.

"He said he is going to need a lot of convincing," Hirst, chief patron of the bill, said of the governor's attitude.

Reaction from local officials in Northern Virginia to Dalton's announcement varied. Dorothy T. Grotos, the newly-installed chairman of the Arlington County Board, said she wasn't surprised.

"He has said this all along," she said, "If Northern Virginia could get together, maybe we could be strong enough to prevail upon him to change his mind."

But Grotos added that she doubted Dalton would waver. "Dalton has made a commitment to the whole (Metro) system. We'll just have to come up with a different way to finance it."

John Purdy, chairman of the Northern Virginia Transportation Commission and an Arlington board member, predicted that the search will continue for an acceptable Metro revenue source. "We have a commitment to seek a new revenue source and we have to follow through. I don't see how we can change because of his threat of a veto."

Alexandria City Councilman Robert L. Calhoun called the governor's position "most unfortunate."

It will make it difficult to expand or even maintain the Metro system that we have," he said. Without a special tax for Metro, "you can forget Sunday service, and Saturday service is vulnerable... I talked to the governor about the subject a year or so ago. He believed then what he believes now but what distresses me is that he is not letting the legislature work its will."