Albanian government announced on Wednesday that a U.S. company has won the tender to buy Albania's state-owned oil company Albpetrol.

The Chicago-based Vetro Energy offered 850 million euros (1.1 billion US dollars) to buy the company, the highest among its competitors.

Prime Minister Sali Berisha said the company would obtain all of Albpetrol's above-ground assets and explore oil and gas fields in Albanian territory for 25 years.

Albpetrol is based in Patos, about 120 kilometers south of capital Tirana. It has six oil fields and four gas fields, with assets valued at about 320 million euros.

The International Monetary Fund had told Albania the day before to use the proceeds from the planned sale of the state-owned oil company to reduce the government debt.

Albania's public debt stands at near 60 percent of the country's GDP, the highest in the Balkans.

Albania's economy contracted 0.2 percent in the first quarter 2012. And the IMF had predicted that the country's economy would grow at 0.5 percent in 2012.