Advancing issues led decliners by a slight margin on Wall Street, but the Dow Jones industrial average was down 28.54 to close at 5,626.88. Volume was light. The America Stock Exchange market Value index gained 1.05 to 568.32, but other broad-market indicators were down. The NYSE composite index was off 0.14 to close at 348.06; The Standard & Poor's 500-stock index was down 1.78 to 649.20; and the Nasdaq composite index fell 1.68 to 1,100.14. Gold at the London late fixing was selling at $396.25, up $1.25.