Futures for crude oil trimmed gains on Tuesday during U.S. morning trading hours, as investors eyed upcoming ISM report on activity in the U.S. manufacturing sector later in the day and the ECB's policy meeting later in the week. On the NYMEX, October delivery futures for light sweet crude were traded at USD96.54 per barrel, giving up 0.1% for the trading session. Earlier in the day, crude was traded at USD97.36,m which was a 0.9% gain.