KIEV, July 13 - The national Nadra Ukrayiny, its daughter company Poltavanaftogazgeologiya, and Kiev-based UkrNafta have signed an agreement to explore and develop the Sakhalinske oil and gas condensate field in Krasnokutsky District in Kharkiv region, Nadra's press service reported on Thursday.

The press service said that the agreement was signed on July 9 through amending the previous agreement between Poltavanaftogazgeologiya and Akhtyrkanaftogaz of UkrNafta.