The index of leading US economic indicators unexpectedly increased in December as the money supply expanded, masking indicators of the deep recession. The Conference Board’s gauge rose the first gain in six months, after a 0.4 percent drop in November, the New York-based group said today. The index points to the direction of the economy over the next three to six months. The Conference Board Coincident Economic Index (CEI) decreased 0.5 percent and the Lagging Economic Index (LAG) decreased 0.4 percent in December. Four of the 10 indicators in today’s report added to the index, led by 0.99 percent rise in the money supply adjusted for inflation, which has the biggest weighting in the index. This reflected increased lending and purchases of securities by the Federal Reserve to unfreeze credit markets and ease borrowing costs.