NEW YORK (Reuters) - Three Greek shipping companies sued U.S. refiner Philadelphia Energy Solutions Inc (PES) for about $600,000, claiming the company did not pay them for fees incurred by crude oil tankers chartered earlier this year, court documents showed.

The lawsuit, entered into New York Southern District Court on Friday, just days before PES, the largest refinery in the East Coast, filed for Chapter 11 bankruptcy protection following a fire that damaged its 335,000 barrel-per-day refinery.

PES exited bankruptcy in August and has struggled financially for several years.

Bayview Shipping Co S.A., Skyview Marine Co S.A., and Gulfview Shipping Co S.A. are seeking a total of $605,160, chartering crude vessels, interest, legal fees and other costs they say PES was responsible for under the charter agreements.

The cargoes, chartered between February and April, were loaded with N’Kossa crude oil, according to the lawsuit.

N’Kossa crude is produced in the Republic of the Congo and is typically lifted as N’Kossa Blend which is a blend of N’Kossa and Kitina crude grades.

At least two of the cargoes were loaded from the Djeno Terminal, according to the lawsuit, which is operated by French oil and gas company Total.

PES was not immediately available for comment.

The refinery is the largest and oldest on the East Coast and has been among the few steady U.S. buyers of African crude since the shale boom.