STILLWATER — Stillwater would get the third computer chip plant that Advanced Micro Devices may one day build in Luther Forest.

Town Attorney James Trainor said at a joint Planning Board-Town Board meeting Monday that his interpretation of existing law is that the company would have to reach a new development agreement with the town for each of the chip fabs. But Matt Jones, an attorney representing AMD, disputed that.

Town Supervisor Shawn Connelly said later he was confident any issues could be worked out.

“We’ll have a discussion” with AMD, Trainor said later. He said the law needs clarifying, and now is a good time to do that. Jones also said the town needs to update its planned development district (PDD) law, not least because it is scheduled to sunset, or go out of existence, at the end of this year. But Trainor said he thought it was important for the town to retain those powers over potential future development of the site.

Representatives from AMD made a presentation to the two boards Monday, and said they hope Stillwater and Malta will adopt identical requirements for their PDDs. For now, the company is committed to only one $4.6 billion chip fab, to be built entirely in Malta, and employing more than 1,400 people. That price tag includes $1.2 billion in state subsidies and credits. If a second chip fab is built, it would be almost all in Malta, while a third would be almost all in Stillwater.

The approximately 230-acre site AMD is planning to buy has space for three chip fabs, one fewer than the four originally contemplated, but each of them larger than previously planned.

Actually, it’s not AMD itself that will be building any chip fabs, but a spin-off called The Foundry in which the government of Abu Dhabi, through a high-tech investment arm, has majority ownership. And it may not be called The Foundry for long, AMD representatives said. They may come up with a new name by the time the deal with Abu Dhabi, which was announced two weeks ago, closes. That closing is seen as happening by the end of this year or early next. Then the company, whatever its name, is hoping to start site preparation by early spring and construction by June, said Steve Groseclose, AMD team leader.

The closing would require approvals from the state’s Empire State Development Corp. along with the federal government and the government of Germany, where AMD has an existing computer chip plant. The state and German approvals are needed to transfer their government subsidies to the new entity. Groseclose said after the meeting that he does not anticipate any requirement for new action by the New York State Legislature.

Michael Relyea, president of the Luther Forest Technology Campus, said after the meeting there will be economic spin-off to Stillwater well before any third chip fab is built. At the moment, most new development in town is residential. After the AMD presentation, the Planning Board was to take up a proposal by VLG Real Estate Developers to build 39 units on 50 acres near Saratoga Lake, up from 29 in a previous proposal. The land was purchased from the Roman Catholic Diocese of Albany, and is near St. Isaac Jogues Chapel on Route 9P and Jib Drive.