The two sides began work Tuesday morning and were talking into the night in an effort to halt the strike, which started at 11 a.m. Monday at about 80 GM facilities across the country.
Both of the people requested anonymity because the talks are private. One said negotiating teams were working out "small details," while the other said that work was almost wrapped up on an innovative plan for the company to pay the union to form a trust and take over responsibility for retiree health care.
But Tuesday night, picketers remained at the GM factories and other facilities, although several industry analysts said they expected the walkout to be short.
A 1970 strike against GM went on for 69 days and helped push the nation into a recession, but industry watchers didn't think that would happen this time.
Both sides have something the other desires - the workers want job security, GM wants the union to take on the burden of retiree health care - and that's the stuff that agreements are made of.
"The UAW and GM understand that a strike is a lose/lose proposition," Deutsche Bank analyst Rod Lache said Tuesday in a note to investors.
Talks broke off Monday when the strike began, but resumed in the afternoon and continued into the evening when weary bargainers broke for a rest. Analysts were encouraged that the talks have continued throughout the strike.