The BBC has signed the biggest ever deal to sell its programmes, agreeing to provide its landmark natural history shows to a new global streaming service run by the Discovery Channel for £300m.
It is the "largest content deal the BBC has ever done" and will last for 10 years, director general Tony Hall said.
BBC natural history shows will be on the new Discovery platform everywhere except the UK, Ireland and China.
The Discovery service is expected to launch by the end of 2019.
The BBC and Discovery will also work together to film new natural history programmes, which will be screened by the BBC in the UK.
Lord Hall said: "The licence fee payer will really benefit from this because whatever money we can make from being part of this streaming service globally, of course we will put that back into more programmes which people here can watch.
"Equally, because we've got this partnership for developing new programmes jointly with Discovery, they'll also see those programmes."
UKTV channels split up
The deal also gives Discovery the streaming rights to hundreds of hours of existing BBC documentaries. In total, the BBC will receive around £30m per year.
Asked whether he was sure that would still be good value in a decade's time, Lord Hall said: "We think we've got a good deal here and think it's appropriate over the 10 years."
The Discovery streaming service is expected to cost US viewers no more than $5 (£3.80) per month.
The BBC and Discovery also announced plans to split up the 10 channels run by UKTV, which they jointly own.
BBC Studios, the corporation's commercial arm, will take full ownership of seven entertainment channels - Alibi, Dave, Drama, Eden, Gold, Yesterday and W - while Discovery will get Good Food, Home and Really.
The BBC is paying Discovery £173m for that deal, which is coming from BBC Studios and is not licence fee money, Lord Hall said.