Aug 4 (Reuters) - Libya's National Oil Corporation said

on Monday it signed a memorandum of understanding with U.S. oil

giant ExxonMobil ( XOM ) after a decade of activity halt in the

North African country due to security reasons.

NOC in a statement said the MoU focuses on conducting

detailed geological and geophysical studies to identify the

hydrocarbon resources in four offshore blocks located off the

northwest coast and the country's Sirte Basin.

In 2013, ExxonMobil ( XOM ), the world's largest publicly-traded

energy company, decided to cut back its staff and operations in

Libya as growing instability no longer justified a major

presence.

The company's decision then came amid growing concern among

international oil companies that the returns on offer in Libya

may not justify the security and political risks that had grown

since the 2011 uprisings that swept the Middle East.

Libya's oil output has been disrupted repeatedly in the

chaotic decade since 2014, when the country divided between two

rival authorities in the east and west following the NATO-backed

uprising that toppled Muammar Gaddafi in 2011.