By Sara Sjolin, MarketWatch

LONDON (MarketWatch) -- European stock markets dropped for a third straight day on Friday as investors digested the latest developments in Ukraine and Portuguese stocks tumbled ahead of the country's exit from its international bailout program

The Stoxx Europe 600 index fell 0.2% to 337.81, after sliding the most in a month on Thursday. Pushing the benchmark lower, shares of Credit Suisse Group AG (CS) fell 1% after The Wall Street Journal late Thursday reported that the bank is expected to pay almost $2.5 billion to settle a tax probe.

More broadly, the European indexes moved lower as the standoff between Ukraine and Russia was back in the spotlight. Bloomberg News reported that Ukrainian troops have moved to force separatists from their eastern rebel bases near the towns of Slovyansk and Kramatorsk, citing acting President Oleksandr Turchynov. Meanwhile, U.S. and U.K. diplomats vowed to impose further industrywide sanctions on Russia if the country undermines Ukraine's presidential election later this month.

Russia's MICEX index fell 0.1% to 1,3781.11 on Friday, while the ruble (USDRUB) fell against the dollar. The greenback bought 34.82 rubles, up 0.1% from Thursday, according to FactSet.

Among other country-specific indexes, France's CAC 40 index lost 0.1% to 4,442.91, while Germany's DAX 30 index gave up 0.1% to 9,641.74. The U.K.'s FTSE 100 index rose 0.2% to 6,829.72.

The moves came after steep losses posted on Thursday, when weaker-than-forecast euro-zone gross-domestic-product data and some disappointing U.S. data sparked a selloff on both sides of the Atlantic.

One of the European benchmarks hardest hit was Portugal's PSI 20 index , which slumped 2.7%. On Friday, the index continued to slide, down 1.8% to 6,764.14, as the country prepared to exit its international bailout program on Saturday.

"Standing on their own too soon perhaps? In light of the 'panic' of yesterday afternoon the two are probably related [in today's selloff]," said Richard Perry, market analyst at Hantec Markets, in emailed comments.

Banks were among hardest hit stocks in Portugal, with shares of Banco Espirito Santo SA off 9.3% and Banco Comercial Português SA down 2%.

Elsewhere in Europe, car makers showed mixed moves after data showed sales growth slowed in April. The Association of European Car Manufacturers said car sales in the European Union totaled 1.09 million vehicles in April, an increase of 4.6% from the same month a year earlier, marking a slowdown after a nearly 11% rise in March.

Meanwhile, Credit Suisse upgraded the European auto sector to overweight from benchmark. Shares of BMW AG rose 0.8% in Frankfurt, while Daimler AG fell 1%. In Paris, Renault SA dropped 3.6% and Peugeot SA lost 1.5%.

Intertek Group PLC slid 3.9% in London after the firm said market conditions remain variable "with good growth in our key product-related business lines, but weak demand in certain other markets.

More must-reads from MarketWatch:

Bill Gross says a 2.5% Treasury yield 'seems fair'

Why a dollar rally is elusive

Virtual Kim Jong-un rides a unicorn into battle against U.S. troops

Subscribe to WSJ: http://online.wsj.com?mod=djnwires