The United States is losing its competitive edge in technology because American industry is spending less on research and because the federal government withdrew much of its support for industrial research at the ends of the Apollo space program and the Vietnam war.

Those were the conclusions of a two-day meeting on U.S. research held by the American Association for the Advancement of Science.

The AAAS experts, also gave other reasons for the decline in U.S. technological superiority. They said American technology is suffering from increased federal regulation that siphons money from research, and from an outdated patent policy that discourages industry from backing research whose products will not win patent protection.

"The patent policy that allows for 17 years of protection may not be enough anymore," Russell W. Peterson, director of the Congressional Office of Technology Assessment, said yesterday at an AAAS press conference. "It now takes so long to ring new products to market that the period of protection may have to be extended."

Still another reason for the decline in U.S. dominance of technology was given by Markley Roberts, research economist with the AFL-CIO, who said that American industry is losing its edge because it is exporting much of the technology it used to keep in the United States.

"Whether it's a Thor-Delta rocket to Japan, an International Harvester tractor factory to Russia or a Piper airplane plant to Brazil," Roberts said, "we are exporting technology to a dangerous degree that also exports production, services and jobs."

In a 120-page report released yesterday, the AAAS pointed out that U.S. industry will spend an estimated $900 million on basic research in 1978. While this is an increase of $250 million due to inflation in the last 10 years.

At the same time, the AAAS said there has been a 27 percent decrease in federal funds granted to private industry for research and development in the last 10 years.

"This trend is clearly attributable," the AAAs said, "to the passing of the peak years of NASA Apollo and Defense-Vietnam R&D," or research and development.

AAAS Director William D. Carey said that one of his chief concerns is that the decline in U.S. technology may have been brought on in part by an overdose of federal regulation.

"It's the uncertainty factor, triggered by incoherent government policies," he said, "that may have led many companies to hedge on innovation, to table what you might call wild-card innovations that take 10 to 20 years to bring forth."

Carey sounded the single note of optimism heard at the two-day session when he praised President Carter's decision to appoint a 15-member committee to study the problems afflicting U.S. industry. Carey said he was pleased that the committee will cover everything from patent, tax and regulatory policies and how they impact industry's views on research spending.

"But at best, we'll have to wait until 1981 or 1982 when Congress answers whatever the committee's findings are," Carey said. "We're talking about 10 years before you see any changes in policy toward industry research."