The United Auto Workers union expanded its strike against General Motors Corp. today, closing 17 key GM plants employing 92,000 workers in 10 states and increasing the chances of an extended shutdown of the world's largest auto maker.

The expansion of the five-day strike, announced at 1 a.m. EDT by UAW President Owen F. Bieber, came after GM's rejection Tuesday night of key aspects of a union "counterproposal" to GM's earlier offers on wages, pensions and job security.

Although both sides had been optimistic about an early settlement, the unprecedented complexity of UAW demands for job security and curbs on GM's use of cheaper foreign-made auto parts left the talks deadlocked after nearly a week of 12- to 20-hour marathon negotiation sessions. Talks began in July.

GM's latest offer, according to sources, included an "income-security" plan that would guarantee wages for an extended period to senior employes in the event of layoffs caused by introduction of new technology or "outsourcing," use of foreign sources of auto supplies.

GM attached a ceiling of about $1 billion to the offer. The UAW has dismissed the cap as inadequate, considering the size of GM's yearly labor costs of about $17 billion and its record profits, expected to top $5 billion in 1984.

The union has declared job security its top priority because it lost more than 250,000 jobs in the 1980-82 recession, and it predicts loss of as many as 1 million of America's 3 million auto jobs because of importation of foreign cars and parts by U.S.-based firms.

The company's last wage offer is estimated to be worth 2.25 percent yearly, but the form of payment is not yet determined, sources said. The union is pushing for 3 percent, a longtime industry standard before the 1980-82 domestic auto slump that resulted in the UAW giving an estimated $4 billion in concessions to the Big 3 auto makers.

GM is reportedly firm on wanting to pay most of any increase in the form of "lump sums" or profit-sharing payments that would not be figured in employes' overtime, vacation pay and other benefits.

Despite today's strike escalation, which meant that nearly 30 percent of the GM work force is idle, both sides remained at the bargaining table. But the UAW announced in late afternoon that "virtually no progress was made," and talks recessed late tonight until Thursday.

GM has indicated that, if the union pushes for costlier job-security guarantees or higher wages, the company will subtract the additional costs from other parts of its last offer.

Pensions, now based at $935 monthly, also figure prominently in the dispute, with the UAW pushing for increases to about $1,200, partly as an inducement to senior workers to retire. GM's pension offer is reported to be about $1,100.

GM also has made an offer involving cash "buyouts," reportedly as much as $50,000, to induce early retirements, but details of that proposal could not be confirmed.

A UAW official involved in bargaining said of the latest company offer, "They have moved a little. Very little."

A GM spokesman would not discuss details of offers exchanged Tuesday night but said, "We are still very encouraged" about chances of settling soon