By Jess Jones ITV has offloaded its entire 50 per cent stake in the digital subscription streaming service, Britbox International, to its joint venture partner BBC Studios. The deal, valued at £255m in cash, is an effort by the broadcaster at “supercharging” its UK advertiser-funded streaming service, ITVX, and bolster its global Studios division. “The sale of 50% of Britbox International means ITV is focused on its core strategic goals of continuing to build on ITVX’s success and growing ITV Studios,” said Carolyn McCall, ITV chief executive. With net proceeds estimated at around £235m, inclu…