July 26 (Reuters) -ICE cotton futures eased more than 1% on Friday as weakness in the oil market and U.S. agricultural markets exerted downward pressure on the natural fiber.

* Cotton contracts for December CTZ4 fell 0.98 cents, or 1.42%, at 67.92 cents per lb at 11:50 a.m. EDT (1550 GMT). The contract is down 3.9% for the week so far.

* The cotton market is under pressure due to a risk-off note that has spread from U.S. agricultural markets into cotton, where bearish trends continue to rule, said Valentin Olah, risk management consultant at StoneX Group.

* In the grains market, Chicago soybean and corn prices fell on Friday but were set for weekly gains of around 4% with a welcome rain forecast for parched U.S. crop belts.GRA/

*Chicago Board of Trade most-active soybeans Sv1 were down 0.4% to $10.74-1/4 per bushel at 1038 GMT. Corn Cv1 was down 0.3% to $4.19-1/2 a bushel.

* The decline in the oil market is weighing on cotton, Olah added.

* Oil prices slipped on Friday and were on track for a third consecutive weekly decline. Lower oil prices make cotton-substitute polyester less expensive. O/R

* The U.S. Department of Agriculture (USDA)report on Thursday showed export sales of 131,300 running bales (RB) of cotton, up 16% from the previous week but down 11% from the prior 4-week average. EXP/COT

* The report also showed net sales of Upland cotton totaling 74,200 RB for 2023/2024, a marketing-year low, were down noticeably from the previous week and the prior 4-week average.

* Meanwhile, Ivory Coast's cotton output for the 2024-2025 season is set to rise by 6% to 367,000 metric tons from 347,922 tons the previous year, Agriculture Minister Kobenan Kouassi Adjoumani said on Thursday.

Reporting by Anushree Mukherjee in Bengaluru; Editing by Tasim Zahid