The Dow Jones industrial average fell15.89 points to close at 5,549.21 after dropping 65.39 points on Monday. Today, trading was moderately heavy on a volume of 431.31 million shares as of 4 p.m. The NYSE composite index lost 1.44 to finish at 345.51. The Standard & Poor's 500-stock index fell 3.22 to 647.24. The Nasdaq composite index fell 6.15 to 1,106.90, and the AMEX market value index fell 1.49 to 563.86. In London, gold closed at $399.05, off $0.90.