Italian energy company Eni said it signed an agreement with PetroVietnam to explore the deep waters off the coast of Vietnam for the next seven years.

"This new agreement confirms Eni's interest to continue and consolidate its presence in Vietnam, where the company returned in 2012 and operates already three offshore exploration blocks," the Italian company said in a Thursday statement.

Eni secured access to so-called Block 122, which covers more than 2,600 square miles off the coast of Vietnam where water depths are up to 6,500 feet.

The exploration period lasts seven years.

Eni offered no estimate of the reserve potential in Block 122.

PetroVietnam said its total production of 2.37 million tons of oil equivalent in May, the last full month for which data are available, was 1.3 percent more than the same time last year.

Eni signed a similar production sharing contract one week ago with China National Offshore Oil Corp.

China and Vietnam are at odds over drilling activity in contested waters of the South China Sea.