CHICAGO, July 16 (Reuters) - Chicago Board of Trade corn futures fell on Thursday, retreating from six-week highs on profit-taking, disappointing export sales and outlooks for milder crop weather in the U.S. Midwest next week, traders said.

• Most-active CBOT December corn CZ26 ended down 5-1/2 cents at $4.64 per bushel after reaching $4.74-1/4 during the trading session, its highest level since June 1.

• The December contract encountered technical resistance after pushing above its 100-day moving average near $4.73.

• Brokers noted scattered cash sales of old-crop grain by farmers.

• Following a week of sizzling heat in the U.S. Corn Belt, forecasts for called for less-threatening temperatures next week and increased chances of showers.

• The U.S. Department of Agriculture reported net export sales of old-crop U.S. corn in the week to July 9 at 315,000 tons, below trade estimates for 500,000 to 1.1 million tons, and sales of new-crop corn of 311,200 tons, versus estimates of 300,000 to 1.1 million tons.

• Worries about tightening global grain supplies underpinned the futures market.

• The International Grains Council cut its forecast for 2026/27 global corn production by 4 million metric tons to 1.306 billion tons following recent heat waves in Europe.

• The IGC also noted increased uncertainty in supplies from the Black Sea region amid escalating hostilities between Russia and Ukraine.