* The Dow Jones industrial average <.DJI> was down 23.35 points, or 0.23 percent, at 10,173.51. The Standard & Poor's 500 Index <.SPX> fell 5.20 points, or 0.47 percent, at 1,091.58. The Nasdaq Composite Index <.IXIC> dipped 10.16 points, or 0.46 percent, at 2,200.64.
* China's central bank has told some banks to increase their reserve ratios by 0.5 percentage point, effective Tuesday, sources said. For details, see [ID:nSGE60P039]
* U.S. home prices in 20 major metropolitan areas slipped in November and were softer than expected in the latest sign that a rebound in the U.S. housing market is tenuous.
(Reporting by Angela Moon; editing by Jeffrey Benkoe)