March 1 (Reuters) - British broadcaster ITV has sold its entire 50% stake in streaming service BritBox International to its joint venture partner BBC Studios for 255 million pounds ($322.09 million), it said on Friday.

The sale will allow ITV to focus on "supercharging" its UK ad-funded streaming service ITVX and growing its global Studios division, it said, adding that it would return proceeds to shareholders via a stock buyback.

($1 = 0.7917 pounds) (Reporting by Yadarisa Shabong in Bengaluru; Editing by Janane Venkatraman)