The executive board of the United Auto Workers union opened its quarterly meeting in Detroit yesterday under mounting industry pressure for early contract talks and wage and benefit concessions.

Top UAW officials met Monday to set the agenda for the three-day meeting, which auto industry officials hope will yield a recantation of the union's vow not to reopen its current contract with Ford Motor Co. and General Motors Corp. before regularly scheduled bargaining next June.

The three-year agreement currently in force expires next Sept. 14. But GM and Ford, facing record dollar losses, desparately are seeking financial relief.

"We've been saying all along that we're ready to start talking and that we're ready now," GM spokesman Cliff Marriott said Monday. But he said that GM--which is the nation's largest automaker and which now has 99,000 workers on indefinite layoff--has "seen absolutely nothing" to indicate that the union will change its opposition to early talks.

GM Chairman Roger Smith said Saturday that more layoffs will occur unless the contract is reopened and the union agrees to concessions. He said "high labor costs" are forcing GM to "outsource," that is, to buy foreign-manufactured parts, usually produced at lower cost.

"The idea behind a contract is to protect peoples' jobs, but right now the contract is working against the union," Smith said.

Similar comments came from officials at Ford, the second-largest domestic automaker, which now has 48,700 workers on indefinite layoff. Ford officials said yesterday that they would like to hear something from the 26-member UAW board. "But no one" from the union "has come to us and ordered us to be on standby for round-the-clock negotiations," a Ford spokesman said.

UAW spokesman Don Stillman said the board recognizes that "the industry is in extremely difficult shape, the worse shape since the Great Depression." The board "obviously is going to discuss that. But I can't predict the outcome of the meeting," Stillman said.

Since 1979, the UAW has given up $1.068 billion in wages and benefits to help Chrysler Corp, the nation's third-largest automaker, avoid bankruptcy. Those givebacks have encouraged GM and Ford to seek similar concessions, but they also have made the union's leadership, which is facing a hard-pressed and restive rank and file, reluctant to give up anything else.

UAW President Douglas A. Fraser told The Washington Post last January that his reluctance to talk early to GM and Ford also sprang from his belief that the two companies were not put at a competitive disadvantage by the union's givebacks to Chrysler. He said then that both companies should "wait to see what the state of the industry is" before seeking early negotiations and concessions.

The industry lost about $1.4 billion in the first 10 months of this year, and is apt to lose substantially more when all the figures are in for 1981. Industry officials believe they can make up a large part of that loss with an early agreement that forgoes cost-of-living allowances, incorporates less costly work rules, and sacrifices some paid holidays.

But, whether or not they go to early talks, union officials have vowed to affix a price to any concessions.

"If they ask for concession, whether it be now or in '82, they'd better be ready to talk about a whole range of things," Fraser said in the January interview. "They'd better be willing to talk about more union representation on the boards of directors, more worker input at the plant level, profit sharing . . . a lot of things formerly considered the exclusive prerogatives of management.

"It won't be that easy," Fraser said.