The seven-year deal to play out all 10 of Flextech's channels, including Living TV, Bravo, Challenge, Trouble, FTN, Living TV2 plus four time-shift channels follows a competitive tender last year and is expected to start around June next year.
According to Flextech's director of commercial operations, Jon James, BBC Broadcast won the tender with its pitch to build a state-of-the-art tapeless post-production and playout unit at the broadcaster's Great Portland Street HQ. BBC Broadcast will build desktop editing suites managed by asset management system MOMS and will also staff the operation.
Eventually programmes and promos will be edited at Great Portland Street and sent digitally to BBC Broadcast's west London playout centre.
The news will come as a blow to Ascent Media's UK operations, which spent over£20m last year buying the London Playout Centre from RTL - Flextech was one of its major clients.
BBC Broadcast director of sales and marketing John Pink told Broadcast: "It's the most significant third party deal we have done in the three years since we have been incorporated and it's worth tens of millions."
BBC Broadcast's playout operation will now handle 74 channels.