* Uncertainty about Greece weighs on commodities, equities
* U.S. corn, soy ratings seen declining in weekly report
* Wheat futures rise on world weather worries (Updates with U.S. trading, analysts' comments, new byline/dateline)
By Tom Polansek
CHICAGO, July 6 (Reuters) - U.S. corn and soybean futures dropped on Monday as lighter-than-expected U.S. rainfall eased fears about soggy Midwest crops while worries over Greece and China led investors to shun many commodity markets.
Corn prices pulled back from 2015 highs notched last week after heavy Midwest rains raised crop concerns and following a tighter-than-expected U.S. Agriculture Department supply outlook for corn and soybeans.
Traders feel that the worst of the rains may now be over, said Jim Gerlach, president of A/C Trading in Indiana.
Fields are drying out after a weekend of clear skies in Missouri and from Illinois to Ohio, added Rich Nelson, chief strategist for brokerage Allendale in Illinois.
Chicago Board of Trade September corn unofficially closed down 2 cents at $4.26-1/2 a bushel. In the previous session, the contract hit its highest price since late December.
August soybeans unofficially closed 16 cents lower at $10.22-1/4 a bushel in a setback from a six-month high touched last week.
Prices weakened ahead of a weekly U.S. crop report that is expected to show corn and soy ratings declined for the fourth straight week.
Uncertainty created by Greece's rejection in a referendum of bailout terms from its creditors added pressure to commodity and equity markets, traders said.
Markets were also unnerved by emergency measures in China to support its tumbling stock markets, which added to worries about the world's second-largest economy and biggest consumer of a clutch of raw materials including soybeans, analysts said.
Concerns about unfavorable weather around the world, including a heat wave in Europe and dryness in Canada, helped lift wheat futures, analysts said.
September wheat futures were up 4-1/2 cents to $5.95 a bushel at the close of trading.
Additional reporting by Gus Trompiz in Paris and Colin Packham in Sydney; Editing by William Hardy and Chizu Nomiyama