NEW YORK (Reuters) - The dollar added to its earlier gains versus a basket of currencies on Monday on data suggesting the U.S. manufacturing sector grew by more than expected in September, returning into expansion territory.

The dollar index <.DXY> was up 0.25 percent at 95.694 after the Institute for Supply Management said its U.S. factory activity index increased to 51.5 last month from 49.4 in August.

(Reporting by Richard Leong; Editing by Chizu Nomiyama)