* CBOT corn ends 4-day fall as harvest, export prospects assessed * Expectation of tight stockpiles counters harvest supply pressure * U.S. weekly export sales update awaited (Updates with European trading, changes byline/dateline) By Gus Trompiz and Naveen Thukral PARIS/SINGAPORE, Sept 22 (Reuters) - Chicago corn futures edged higher on Wednesday, steadying after a one-week low in the previous session as the market assessed mixed reports from an advancing U.S. harvest and sought a clearer picture of export prospects. Wheat tracked corn higher to also recover from a one-week low, with support from brisk importer demand. Soybeans also ticked up, underpinned by rising vegetable oil futures as traders awaited Thursday"s weekly U.S. export data for further clues on Chinese demand. The most-active corn contract on the Chicago Board Of Trade (CBOT) was up 0.5% at $5.19-3/4 a bushel as of 1059 GMT. On Tuesday, the contract touched a one-week low as it fell for a fourth straight session. The U.S. Department of Agriculture (USDA) said after Monday"s market close that the U.S. corn harvest was 10% complete, ahead of the five-year average of 9% for this time of the year. "People are getting a better idea of the crop - enough to take risk off the table but not enough to change the idea of tight stocks in the U.S.," Michael Magdovitz, commodity analyst with Rabobank, said. "I think the break in prices probably spurred a bit of commercial buying." The USDA"s update on Monday rated 59% of the U.S. corn crop in good-to-excellent condition, up 1 point from the previous week, an improvement that added to supply pressure. But analysts noted reports of disappointing yields in some early corn harvesting that were helping keep prices well supported above $5. CBOT wheat was up 1.1% at $6.97-1/2 a bushel and soybeans inched up 0.2% to $12.76-3/4 a bushel. A slowdown in U.S. export loadings due to damage caused by Hurricane Ida, as well as a rally in the dollar, has tempered U.S. export sentiment. Thursday"s weekly U.S. export sales report would be monitored by the soybean market in particular to see if Chinese demand picks up ahead of the peak loading season for U.S. soy. "Right now, export sales are not sufficient to give confidence to the market, that"s why we"ve seen soybeans trickling below $13," Magdovitz said. Prices at 1059 GMT Last Change Pct End Ytd Pct Move 2020 Move CBOT wheat 697.50 7.25 1.05 640.50 8.90 CBOT corn 519.75 2.75 0.53 484.00 7.39 CBOT soy 1276.75 2.75 0.22 1311.00 -2.61 Paris wheat Dec 247.50 3.25 1.33 192.50 28.57 Paris maize Nov 217.75 2.00 0.93 219.00 -0.57 Paris rape Nov 609.50 3.50 0.58 418.25 45.73 WTI crude oil 71.56 1.07 1.52 48.52 47.49 Euro/dlr 1.17 0.00 0.09 1.2100 -3.02 Most active contracts - Wheat, corn and soy US cents/bushel, Paris futures in euros per tonne (Reporting by Gus Trompiz and Naveen Thukral; Editing by Devika Syamnath and Emelia Sithole-Matarise)