U.S. stock index futures pointed to a lower open on Tuesday morning as traders eyed a continued decline in oil prices and a probable March rate hike.
The Producer Price Index (PPI) rose 0.3 percent in February. Earlier on Tuesday, the National Federation of Independent Business (NFIB) said its small business optimism index fell 0.6 points to 105.3 last month.
U.S. crude oil prices gave up earlier gains to hit a fresh three-month low after a monthly OPEC report showed many members continued to pump above their quotas.
WTI traded 1.5 percent lower below $48 a barrel, while brent crude traded around $50.78 a barrel, down about 1.1 percent. The Energy Select Sector SPDR Fund (XLE) fell 0.7 percent in premarket trade.