GEORGETOWN - Exxon Mobil Corp said on Thursday the U.S. oil major along with its partners have made an oil discovery offshore Guyana, which adds to the previously estimated 5.5 billion barrels of oil-equivalent.

The discovery was in the Turbot area of Stabroek Block, which is expected to become a major development hub, Exxon said.

This is the thirteenth discovery on the block, which is part of one of the biggest oil discoveries in the world in the last decade.

Hess Corp and China National Offshore Oil Corporation are part of the consortium.