Chevron said on Tuesday it would search for oil and gas south of Malta, which lies between producing Mediterranean nations Libya, Italy and Tunisia but has not got any production itself yet.
Exploration studies will be based on existing data rather than newly drilled wells.
Chevron's portfolio in the Mediterranean includes operating stakes in Israel's Leviathan and Tamar gas fields and the Aphrodite field being developed offshore Cyprus.
Chevron also has exploration blocks offshore Greece and Egypt.
U.S. rival Exxon has also been expanding its portfolio in the Mediterranean
(Reuters - Reporting by Shadia Nasralla, Editing by Louise Heavens)