CAIRO, Oct 18 (Reuters) - The head of Egypt's Suez Canal Authority announced on Saturday the government had signed a contract with six international firms for the dredging of the new Suez Canal.

The six companies, in a consortium named "Challenge Coalition", are National Marine Dredging Company of the United Arab Emirates; Royal Boskalis Westminster and Van Oord, both based in the Netherlands; Jan de Nul Group and Deme Group, both of Belgium; and U.S.-based Great Lakes Dredge and Dock Company.

Work on the project will begin this week, said Lieutenant General Mohab Memish, head of the Suez Canal Authority. The project is scheduled to be completed by August 2015.

Memish said the Authority would be responsible for dredging one of the six zones, while the contracted firms would dredge the remaining five. (Reporting by Stephen Kalin and Mahmoud Mourad; Writing by Maggie Fick; Editing by Andrew Roche)