* FTSEurofirst 300 index falls 0.7 pct
* Adidas, Banco Espirito Santo shares slump
* Worries about U.S. monetary policy hit sentiment
By Atul Prakash and Blaise Robinson
LONDON/PARIS, July 31 (Reuters) - Europe's FTSEurofirst 300 index of top shares slipped to a two-week low on Thursday, led lower by Adidas after the group warned about business in Russia, while Argentina's default also rattled investors.
The broader market was dragged down by sharp declines in some individual stocks, with German sportswear company Adidas falling 13 percent and Portugal's Banco Espirito Santo sinking nearly 50 percent at one point to a record low after booking a 3.6 billion euro first-half loss.
BES, down 27 percent, pushed Portugal's benchmark PSI 20 index 2.4 percent lower to underperform the wider market, while Adidas dragged Germany's DAX 0.9 percent down after saying it will scale back plans to expand in Russia and overhaul its golf business.
Spanish stocks also came under pressure, with Madrid's IBEX dropping 1.7 percent, as traders cited worries over Spanish companies' exposure to Latin America after Argentina defaulted on its debt on Thursday.
At 1114 GMT, the FTSEurofirst 300 was down 0.7 percent at 1,356.82 points after falling up to 1,353.67, the lowest since mid-July, with analysts saying the sell-off might continue on worries about further monetary tightening in the United States.
"The biggest worry is the uncertainty about the U.S. monetary policy. The strong GDP data and an improving economic outlook have raised the risk of an early rate hike," Philippe Gijsels, head of research at BNP Paribas Fortis Global Markets in Brussels, said.
"Tomorrow's U.S. non-farm payrolls data may further cement the view that a rate rise could happen earlier than expected."
Data showed on Wednesday the U.S. economy rebounded sharply in the second quarter as consumers stepped up spending and businesses restocked, while Friday's data is likely to show U.S. nonfarm payrolls rose by 233,000 in July, which would mark the sixth month with job growth above 200,000.
Overall on Thursday, corporate results from European blue-chips were relatively positive, with shares in Sanofi surging 3.6 percent after the French drugmaker raised its full-year profit forecast while Royal Dutch Shell gained 3 percent after reporting a 33 percent increase in quarterly earnings, beating analyst forecasts.
"Despite some decent earnings from a number of blue-chips, the market is stuck in a range, with many negative catalysts including Argentina's default at the forefront of investors' minds," said Lionel Jardin, head of institutional sales at Assya Capital, in Paris.
About 40 percent of STOXX Europe 600 companies have reported results so far in the earnings season, of which 55 percent have met or beaten profit forecast, according to Thomson Reuters StarMine data.
On average, quarterly profits are up 7.1 percent year-over-year, data shows, but revenues are down 1.5 percent, fuelling concerns over the earnings trend.
Europe bourses in 2014: link.reuters.com/pap87v
Asset performance in 2014: link.reuters.com/gap87v
Today's European research round-up (Editing by Janet Lawrence)