Norwegian energy company Statoil said it sold its corporate offices in Stavanger and signed a 15-year lease with new owners in an effort to release capital.

For an undisclosed sum, the Norwegian energy company said it sold its head office building to U.S. real estate investment firm Colony Capital, Inc. The property was valued at more than $320 million and, in exchange for the sale, Statoil said it signed a 15-year lease with the new owners.

"The agreement is the result of a successful sales process, and we believe that Colony Capital is a long-term and good owner of the building," Statoil senior vice president Kare Thomsen said in a statement. "As lessee Statoil will still be responsible for operation and maintenance of the property, while the sale releases capital for developing our core activities."

The low price of oil is forcing most energy companies to spend less on exploration and production, a market situation reflected in low rig numbers. Statoil said it spent $355 million on exploration in the first quarter, down from the $433 million spent during the first quarter of 2014.

Low oil prices also mean lower earnings and for Statoil, first quarter earnings of $3 billion was about half as much as reported for first quarter 2014.

In a full-year report, the company nevertheless said equity production of 1.93 million barrels of oil equivalent for 2014 was a 4 percent increase from the previous year. Statoil said results show it's among the leading companies in the industry.