KIEV, Aug. 17 - UkrGaz-Energo, an energy trader of which Russian gas monopoly Gazprom controls at least 25%, may invest in development of an offshore gas field in the Black Sea, a source at Naftogaz Ukrayiny said Friday.

Naftogaz, which has been experiencing financial difficulties, recently approved a decision to invite UkrGaz-Energo as a partner to invest in exploration and development of the field near Odessa, the source said.