(Changes day in paragraph two)
* STOXX down 0.2 percent
* Air France surprises markets
* Apple beat fails to boost tech
By Julien Ponthus
LONDON, Aug 1 (Reuters) - European shares retreated slightly on Wednesday as a mixed batch of corporate earnings failed to offset concerns about the U.S.-China trade conflict and subdued euro zone manufacturing growth.
Caution was also palpable ahead of the Federal Reserve's decision, due on Wednesday, with the U.S. central bank expected to keep interest rates on hold before two hikes later this year.
By 0909 GMT, the pan-European STOXX 600 Germany's DAX were each down 0.2 percent and France's CAC 40 was up 0.1 percent.
Basic materials was the worst-performing sector, down 1.8 percent as copper prices slid following reports that the United States may propose a higher, 25-percent tariff on $200 billion of Chinese imports.
Rio Tinto added to pressure on the sector as disappointing results sent its stock down 4.3 percent despite news of an additional $1 billion share buy-back.
British airline services company's BBA Aviation was the worst performing STOXX 600 share with a 13.7 percent fall to a near 1-1/2-year low after disappointing results.
On the upside, travel and leisure stocks got support from Air France-KLM, which rose 7 percent after second-quarter results beat estimates despite recent strikes.
France's BNP Paribas reported forecast-beating second-quarter profits and saw its shares rise at the opening.
In the UK, Lloyds Banking shone, rising 1.8 percent after reporting a 23-percent jump in first half pre-tax profit.
Apple's positive trading update was not enough to help tech stocks, with the sector losing 0.2 percent.
In other earnings related moves, Belgium's Telenet Group jumped 7.6 percent after announcing an extraordinary dividend and supportive first-half results. (Reporting by Julien Ponthus Editing by Louise Ireland)