European shares fell in early trading Tuesday, snapping a four-day rally, in cautious trading ahead of a vote in Slovakia to extend the region's rescue fund.

At 0709 GMT, the FTSEurofirst 300 index of top European shares was down 0.6 percent at 958.02 points, after rising 1.7 percent on Monday, when it extended a rally to four days, on optimism that policymakers were addressing the region's debt crisis. U.S. shares also rose for a fourth day.

Stocks were lower across the board on Tuesday, with the STOXX Europe 600 Basic Resources Index and STOXX Europe 600 Autos Index down 1.4 and 1.8 percent respectively, giving up some of the strong gains of the previous session.

Traders were cautious ahead of a vote in Slovakia to extend the euro zone rescue facility. Slovakia is the last member the 17-member bloc yet to vote on a deal agreed by its leaders in July to boost the size and powers of the European Financial Stability Facility.

The Slovakian vote is on a knife-edge. It could go either way. But (if they vote against) they can vote again, to get -- from the European perspective -- the right result. The market is thinking that they are holding out, and playing hardball, Jeremy Batstone-Carr, strategist at Charles Stanley, said.

(Reporting by Brian Gorman)