U.S. supermajor Chevron announced it has shut down its offices in Lithuania and sold off half of its interests in the country.

"Chevron closed its office in Vilnius, Lithuania," a statement posted Tuesday on its website said. "The company has divested its 50 percent equity interest in [joint venture] LL Investicijos."

In a separate statement, Swedish energy company Tethys Oil said it increased its stake in the Rietavas license in Lithuania from 14 percent to 30 percent as part of the joint venture in the country with Chevron.

"The work program, focused on evaluation of the license area for conventional and unconventional hydrocarbon potential, continues as planned and is not affected by Chevron's exit," the Swedish company said.

Chevron in a 2013 annual report said three exploration wells had been drilled into the Rietavas block and results were under evaluation. No estimate of the reserve potential was given.

Britain, Poland and Lithuania are among the handful of members of the European Union said to be rich in shale natural gas deposits.

No value of the transaction was disclosed. Chevron gave no reason for the divestment.