New Zealander Michael Fay met with Dennis Conner's America's Cup team in San Diego yesterday, but the two sides made no apparent headway in complex negotiations over Cup races next September. Fay's two-hour session with Malin Burnham, head of Conner's Sail America Foundation, was their first since Fay's surprise Cup challenge was filed in July.

After the meeting, Burnham repeated assurances Conner will defend the Cup against Fay's huge, 90-foot-waterline challenger next fall, but again refused to name a site until 90 days beforehand and vowed to allow no challengers but New Zealand to compete.

Said Burnham's assistant, Tom Ehman, "They {Fay and Burnham} agreed to disagree. We're going to settle this thing on the water."

Fay pushed Conner's forces into a premature defense of the prize they won off Australia last winter by filing a challenge July 17 under long-neglected, antiquated rules of the 100-year-old Cup Deed of Gift.

Conner had planned a defense four years hence, and today Burnham renewed that pledge, saying, "If we are successful {against New Zealand} we will host a modern America's Cup regatta in 12-meter yachts off San Diego in 1991."

Fay hoped in yesterday's meeting to convince Burnham to name San Diego as the September racing site and to allow other nations to race for the right to challenge.

He also hoped to convince Burnham that Sail America was obliged under the rules to race in a boat similar to the massive, single-hulled sloop New Zealand is building. Recent reports indicated Sail America believes a fast trimaran or catamaran would be legal, which could make the race a runaway.

But Sail America design coordinator John Marshall offered no promises on hull design yesterday.

"Our job is, in the short time reamining . . . to design a superior boat. She may well be very similar to Fay's," he said.

"On the other hand," said Marshall, "we hope and believe that in America we will identify other concepts more promising still.

"Who knows? Perhaps a lighter, smaller, more efficient craft crewed by 10 or 11 good men can outmaneuver and outsail Fay's monster yacht."

Fay will head back to New Zealand, where his yacht is under construction and due for launch in March. Sail America promised to introduce its sailing team and some design concepts at a press conference early next month.

Meanwhile, in Toronto, the Canadian Force 12 North team announced its intention to join the September regatta if other challengers are permitted.

That brings to three the number of additional challengers who want to compete. Australia's Alan Bond and Britain's Peter deSavary are building 90-foot-waterline boats, and Bond has promised to sue if Sail America bars them from racing.