European shares fell early on Thursday, tracking Wall Street lower, after ratings agency Fitch warned that the outlook for U.S. banks could deteriorate if the euro zone sovereign debt crisis is not resolved soon.

At 8:08 a.m., the FTSEurofirst 300 <.FTEU3> index of top European shares was down 0.2 percent at 969.02 points.

Fitch Ratings warned that it may reduce its stable rating outlook for U.S. banks because of contagion from problems in troubled European markets.

The STOXX Europe 600 Banking Index <.SX7P>, with many constituents exposed to the euro zone periphery, fell 0.7 percent.

Some strategists said European policymakers would need to make fundamental changes to the nature of the single currency.

Everyone's looking around saying we should be doing something but no one is making any decisions. It can't carry on like this. But how many weeks have we said that for? Germany needs to lead the way in a euro core, and then think about how we handle the periphery, said Justin Urquhart Stewart, director at Seven Investment Management.

Spain and France are both due to hold bond auctions later in the session, providing a test of investor confidence. Rising sovereign bond yields have been a major factor in driving equity markets lower this week.

(Reporting by Brian Gorman)