LUANDA, Sept 3 (Reuters) - Chevron ( CVX ) has signed a

preliminary agreement with Angola's national oil and gas

concessionaire ANPG to explore for oil in the country's offshore

block 33/24, the U.S. oil major said on Wednesday.

The risk services contract with Angola's National Oil, Gas

and Biofuels Agency was signed on the first day of an energy

conference in the country.

"The execution of the RSC remains subject to regulatory

approvals," Chevron ( CVX ) said in a statement.

The deep-water block is found in the Lower Congo Basin, and

is adjacent to the prolific Block 17 and Block 32.