* STOXX 600 down 0.7 pct
* Italian banks shine
* Biomerieux jumps, Bayer falls (Adds quotes, shares)
LONDON, Sept 5 (Reuters) - European shares traded lower on Wednesday as trade tensions and growing worries about emerging market currencies cut investor appetite for risky assets.
At 0826 GMT, the pan-European STOXX 600 was down 0.7 percent, with losses spread across industry sectors and trading centres despite data showing that Euro zone business activity accelerated slightly in August.
A rare glimmer of optimism lifted Italy's banks, buoyed by deputy Prime Minister Matteo Salvini saying that Rome would "try to be good" with respect to European Union budget rules.
Rating agency Scope also issued a note saying that while "volatile politics have reignited fears around Italian banks", there has been progress on non-performing loans.
Shares in UBI Banca, Banco BPM and Mediobanca were up by 3.2 percent, 2.5 percent and 2.1 percent respectively.
Corporate announcements also triggered strong swings, most notably in French pharmaceutical group BioMerieux which was the best performer on the STOXX 600 index, up by 8.3 percent after better than expected first-half results and a raised 2018 outlook.
In the same sector, Bayer lost 2 percent after reporting a disappointing 3.9 percent gain in underlying core earnings for the quarter.
Overall, the European Healthcare sector was down 0.8 percent.
Another French firm was also among the highest risers. Outdoor advertising group JCDecaux added 6.8 percent after a rating upgrade by BofA Merrill.
British betting company William Hill jumped 4.5 percent after it signed a 25-year sports-betting partnership with casino operator Eldorado Resorts, which investors see as a major step in its U.S. expansion.
The biggest faller was Denmark's Ambu whose shares sank 13 percent after reports of a shareholder selling his stock at a discount.
Snuff and cigar maker Swedish Match fell 5.2 pct after an institutional investor sold a stake of 4.3 million shares at a discount. (Reporting by Julien Ponthus; Editing by Catherine Evans and Alexander Smith)