On Monday European stocks slid, halting a four-day rally for the Stoxx Europe 600 Index, as investors speculated that Greece may not receive a payment that would help it avoid default. U.S. futures and Asian shares also fell.

Deutsche Bank AG led banks lower after Germany’s ruling party lost another regional election. UBS AG slipped 1.2 percent after saying its loss from unauthorized trading amounted to $2.3 billion. Mining companies and oil producers fell as base metals and crude oil dropped, while Michelin & Cie. declined after Morgan Stanley downgraded the tiremaker.

The benchmark Stoxx 600 retreated 2.1 percent at 10:21 a.m. in London, paring last week’s 2.5 percent advance.

Greece’s ability to avoid default hangs in the balance this week as international monitors prepare to assess whether Prime Minister George Papandreou can meet the conditions of rescue loans. The Greek leader canceled a U.S. visit that was to begin yesterday, saying he needed to remain in the country for a “critical” seven days.

European Union and International Monetary Fund inspectors hold a teleconference during the day with Greece’s Finance Minister, Evangelos Venizelos, to judge whether the government is eligible for an aid payment due in October.

Separately, German Chancellor Angela Merkel’s party lost a regional election in Berlin, the last of seven state ballots this year in which voters have punished the governing coalition parties for their handling of the sovereign-debt crisis.

Stocks rallied around the world last week after Germany and France said Greece will remain a euro member and the European Central Bank announced coordinated measures with the Federal Reserve to ensure the region’s lenders have sufficient U.S. dollars.

Standard & Poor’s 500 Index futures expiring in December retreated 1.9 percent, following the benchmark gauge’s 5.4 percent gain last week. The MSCI Asia Pacific Index lost 1.6 percent today, falling for the first time in three days.