Detroit officials and union bargainers met for the first time since 7,000 striking workers rejected a contract proposal, but there was no sign of an immediate settlement in the 15-day walkout. Another meeting was scheduled for this afternoon. Mayor Coleman A. Young has said that the city has no more money to sweeten the proposal, which was rejected by a 3-1 margin Monday by the union's rank-and-file. The proposal called for raises of 5% in the first year (plus a $500 bonus), 2.5% in the second year and a third-year pay raise tied to the city's fiscal health. The union had sought a 26% raise over three years.