UPDATE 1-Canadian National Railway says oil spills after train derails in U.S.

U.S.@ (Adds comment from Exxon in paragraph 6)

July 3 (Reuters) - Canadian National Railway Co said about 20,000 gallons (76,000 liters) of oil was released following a freight train derailment at Plainfield, Illinois, on Friday, according to a filing with state pollution regulators.

The cause of the derailment was unknown, a filing with the Illinois Emergency Management Agency said on Saturday.

Local media reports estimated the spill to be 45,000 gallons.

The incident occurred when 20 cars of a Canadian National Railway Co freight train, carrying crude for Exxon Mobil Corp to Louisiana, went off the tracks, the Chicago Tribune said in a report on Saturday, quoting officials.

"No one was injured in the derailment. Officials confirmed that oil leaked from two of the cars on the Canadian National freight train, and a possible third car was leaking oil," the report added. (Source: http://trib.in/2uAFObw)

Exxon said in an emailed response that CNR confirmed the train was transporting crude oil from Canada to Louisiana, but the oil major did not confirm whether it was its shipment. It, however, added that operations at its Baton Rouge refinery in Louisiana were normal.

According to a report on the news website of Northwest Herald, most of the derailed cars were cleared by Saturday and the rest were expected to be removed from the site by Sunday.

Cleanup operations of the spilled crude was expected to take a few days, the report said. (Source: http://bit.ly/2t846vY) (Reporting by Vijaykumar Vedala in Bengaluru; Editing by Edmund Blair and Marguerita Choy)