Shutterstock

General Motors  (GM - Get Report) shares traded higher Thursday even fter the carmarker reported a sharp third-quarter slump in China sales, adding to domestic pressures linked to the ongoing strike by United Auto Workers union employees that have shown little signs of progress.

GM said sales in China, the world's biggest car market, fell 17.5% over the three months ending in September, the fifth consecutive decline that takes its nine-month total to around 2.26 million. Slowing growth in China, as well as the impact of its year-long trade dispute with the United States, has clipped American carmarker's share of the China market to just under 10%, according to official industry data, while German and Japanese rivals have seen solid year-to-date gains.

GM's China struggles aren't the only issue for investors, either, as the nation-wide UAW strike extends into its third week, keeping some 48,000 workers at home or on the picket lines as union officials negotiates for higher pay, a greater share of group profits and enhanced job security.

UAW vice president Terry Dittes, who is leading the negotiations, said earlier this week that talks had taken a "turn for the worse", adding the Detroit-based carmaking icon "has shown an unwillingness to fairly compensate" its members. GM insists that it's negotiating "in good faith with very good proposals that benefit employees today and build a stronger future for all of us."

GM shares rose 1.64% to $4.70 in trading Thursday, leaving the stock some 11.5% lower since the UAW strike began on Sept. 16.

GM's China woes also highlight a key proposal in the UAW's bargaining position, which Dittes laid out in a letter to union officials published earlier this week that called on the carmaker to produce its entire fleet in domestic plants and assembly facilities.

"We have made it clear that there is no job security for us when GM products are made in other countries for the purpose of selling them here in the USA.," Dittes wrote. "We believe that the vehicles GM sells here should be built here. We don't understand GM's opposition to this proposition."

At present, around three quarters of GM's U.S. sales are made from cars built in plants based in Mexico, with a smaller portion coming from a factory in Oshawa, Ontario. 

Last year, GM said it would shutter five plants in North America, including in Maryland, Michigan and Ohio and cut 15% of the salaried workforce, including 25% fewer executives, as part of an effort to streamline decision making.