A joint-venture company operated by General Motors Corp. and Toyota Motor Corp. today unveiled its first product -- a metallic light-blue, 1.6-liter subcompact front-wheel drive car called the Chevrolet Nova.

The hybrid sedan is a derivative of the Toyota Sprinter, which originally went on sale in Japan in 1968 but was completely redesigned last year.

The Nova version is the first of 200,000 models that will be made here through 1986 by the joint-venture company, New United Motor Manufacturing Inc.

Under the terms of the agreement signed by GM and Toyota on Feb. 17, 1983, NUMMI is an equally owned company that is scheduled to operate for 12 years. But the agreement also gives Toyota the right to produce its own cars at the NUMMI plant for U.S. sales.

NUMMI, at peak production, will roll out 250,000 Novas annually and employ about 2,500 hourly workers. GM's estimated 5,000 Chevrolet dealers will start selling the new car as a 1985 model late next spring.

But more than sales is riding on the success of the Nova, according to auto industry officials and analysts.

NUMMI, which began production on schedule Dec. 4, is designed to combine the best of the U.S. and Japanese automotive systems in an attempt to "turn out the highest quality car in the world," Toyota Executive Vice President K. Kusunoki said.

The outcome of that experiment, which also involves the active participation of the United Auto Workers Union, could help redefine industrial labor-management relations in this country and mean more Japanese companies setting up shop in the United States, according to Kusunoki and others.

Toyota is the third Japanese company to begin production on U.S. soil. Nissan is producing subcompact trucks and passenger cars in Smyrna, Tenn.; and Honda is assembling Honda cars in Marysville, Ohio. Mazda last month announced its intentions to build a new passenger car assembly plant in Flat Rock, Mich.

"It is encumbent on us, regardless of the difficulties facing us, that we make this system work," said Kusunoki, who also said that the joint-venture at the former GM assembly plant here is a key part of Toyota's drive to internationalize its business.

The "system" about which Kusunoki spoke partly entails the use of worker groups and teams on the plant floor. Each group and team will be responsible for solving its own production and human relations problems, plant officials said.

It is a different world from veteran auto workers and UAW workers such as 45-year-old Les Myers, a team leader, and 40-year-old group leader Curtis Spears.

Both Spears and Myers recently spent three weeks in Japan learning the Toyota way. Both said that the new way is better.

"The new system emphasizes training, training and more training," Myers said. "They make sure that you know what you're doing, which is why Japanese cars are so good."

Also, working out production problems in groups and teams keeps those problems from becoming plantwide problems, which could get all messed up with union politics," Spears said.

All of the details of the NUMMI-UAW relationship have not been worked out, and probably won't be for another three months, according to plant officials. Currently, there are some 400 hourly workers and 100 salaried employes on the job here.

Toyota officials primarily will be responsible for running NUMMI's manufacturing and production systems. GM, through its Chevrolet division, will be responsible for marketing the Nova, which first appeared in the U.S. auto market as a Chevrolet product in 1962.