CME Group Inc.'s (CME) new, reduced grain and oilseed futures trading hours will begin Sunday evening.

The new schedule, a response to customer complaints that longer hours were reducing liquidity and increasing operating costs, trims trading hours to 17 1/2 hours per day, down from the existing 21-hour schedule.

The new schedule, unveiled in March, cuts afternoon hours and creates a 45-minute pause in trading in the morning before open-outcry, or "pit," trading begins.

Futures contracts for grains such as corn, rice and wheat, along with soybeans and soybean products, will open Sunday at 8 p.m. ET, remaining open overnight until a 45-minute 'pause' begins Monday morning at 8:45 a.m. ET. Electronic and open outcry trading will both re-open at 9:30 a.m. and close at 2:15 p.m. ET. That schedule will continue throughout the week until the market closes on Friday afternoon.

Since last May the market has traded electronically around the clock except for a three-hour break between 3 p.m. and 6 p.m. The CME expanded the hours last year in response to new grain futures contracts launched by the rival IntercontinentalExchange Inc. (ICE).

Prior to last year's expansion the market was open 17 hours per day.

Write to Ian Berry at ian.berry@dowjones.com

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(END) Dow Jones Newswires

April 05, 2013 11:39 ET (15:39 GMT)