* Wheat firms on global supply concerns * Soybeans fall, export demand caps losses * Corn edges lower, set to finish week up 2% CANBERRA, Sept 17 (Reuters) - U.S. wheat futures edged higher to linger near a more than one-week high on Friday, as concerns about global supplies set the grain on track for a weekly gain of nearly 4%. Corn edged lower but was set to advance 2% for the week, while soybeans also fell, though losses were checked by recent Chinese demand for the commodity. The most-active wheat futures on the Chicago Board of Trade were up 0.1% at $7.13-1/4 a bushel, as of 0400 GMT, having closed 0.1% higher on Thursday when prices hit a Sept. 8 high of $7.16-3/4 a bushel. Wheat was set for its biggest weekly gain in five, with analysts and traders attributing the rise to concerns about global supplies. “Production in several regions is not looking as good as did earlier this year and that has the market concerned,” said a Melbourne-based grains trader who declined to be named as he is not authorised to talk to the media. Strategie Grains on Thursday sharply lowered its projection for world output, partly due to a reduced estimate for the European Union. Statistics Canada earlier this week issued lower-than-expected estimates for Canadian wheat production, while France reduced its soft wheat crop estimate. In Russia, analysts said farmers are expected to sow less winter wheat for next year’s harvest. Soybean futures were down 0.7% at $12.87-1/2 a bushel after closing up 0.1% in the previous session. Soybeans are down nearly 0.5% for the week, the second straight weekly loss. Analysts, however, said losses were checked by Chinese demand. The U.S. Department of Agriculture (USDA) reported that China bought 132,000 tonnes of U.S. soybeans after cancelling the same volume on Wednesday. Corn futures were down 0.3% at $5.28 a bushel after closing down 0.8% in the previous session. Corn has gained more than 2% for the week, poised for the first weekly gain in three. Analysts said corn was under pressure amid tepid export demand for U.S. supplies. The USDA on Thursday reported U.S. corn export sales in the week ended Sept. 9 were 248,900 tonnes, below trade expectations. (Reporting by Colin Packham; Editing by Devika Syamnath)