The Arlington County board reaffirmed its support yesterday for a Metro financing agreement but said the transit system -- not Arlington and other local jurisdictions -- must be legally responsible for repayment of the $1 billion debt.

County Board Vice Chairman Walter L. Frankland, Jr., who represents Arlington on the Metro board, plans to ask the full Metro board to adopt the resolution at a special session Monday.

At that meeting the Metro board will decide whether to authorize general manager Richard S. Page to sign the agreement with the federal government. Under the agreement, Metro would pay one third of the cost of retiring the debt and the federal grovernment would pick the remaining two-thirds.

The agreement, which took 18 months to produce, would resolve the biggest issue separating the federal and local government on Metro's long-range financing. Some local jurisdictions have balked at approving the agreement.

Two days ago federal officials warned Metro board members that failure to sign the agreement by Sept. 30 would mean the immediate loss of$275 million in construction funds. After that meeting Metro Board Chairman Jerry A. Moore predicted the agreement would be signed.

Moore's prediction was echoed by Frankland yesterday who said he raised the issue in order to get reaction from other Arlington officials before Monday's vote.

"It's funny," said Frankland, a frequent critic of Metro financing. "I'm the only one down there now who said he would vote for it."

After Frankland expressed reservations about the agreement yesterday, Arlington fiscal analysis chief Anton S. Gardner urged him to support it. "It's my estimation that there will be at least four or five votes in favor of the agreement," said Gardner who has spent the past two days meeting with officials of other jurisdictions on the proposal.

At Gardner's suggestion the board then unanimously directed Frankland to introduce a resolution which underscores the responsibility of Metro to repay the debt.

In other action the board voted to rezone a small tract of land one block from the county courthouse in order to permit construction of a 12-story office building. That site is now occupied by the 72-unit moderate cost Arlington Court garden apartment project.

Several tenants unsuccessfully urged the board to bar the zoning change because, in the words of one, "students, young married couples, the elderly and newcomers to the U.S., who live in the buildings can't afford to move." However, an official of Arledge Real Estate, which owns the project, told the board he would relocate tenants in similar nearby buildings that his firm owns.

The board voted to grant the rezoning, becuase county land use plans show high rise development around Metro stations. The apartment complex is located a quarter of a mile from the site of the Courthouse Metro stop which is scheduled to open in December.

That same issue, the type of development to be allowed around Metro stations, came before the Alexandria City Council yesterday. There a spokesman for the Richmond, Fredericksburg, and Potomac Railroad threatened to cancel plans for a hotel complex around the planned King Street station if high-rise restrictions are imposed on the land.

Railroad spokesman Donald Hunt, told members of the Council at a public hearing that lower "height limitations would probably make the project unfeasible."

Hunt spoke in connection with recent proposals from the City Planning Commission to limit new construction around the Metro station to 88 feet in most cases, and up to 110 feet under special circumstances. The current height limit is 150 feet.

Bill Livingston, a resident of the Rosemont neighborhood adjacent to the Metro site, criticized the proposed limits as encouraging "a mini-Crystal city . . . . Those plans will radical change the nature of Old Towne, and the downtown Alexandria area," he said. The council did not act on the proposals.