The privatisation of the BBC's main commercial arm could undermine the Britishness of the broadcaster's programming and add £10 to the licence fee , director general Tony Hall has warned.
Speaking on the second day of the Royal Television Society convention in Cambridge, Lord Hall said the corporation faced challenges to protect the "degree and quality" of its programming as its Royal Charter is reviewed.
He added that the corporation would strongly resist any plans to privatise BBC Worldwide - which helps fund the broadcaster by selling top shows like Top Gear and Sherlock abroad - saying its was "indivisible" from the rest of the organisation.
The prospect has been the subject of speculation over a number of years and was most recently raised in the Government's Green Paper on the future of the BBC published earlier this year.
Lord Hall said all of the broadcaster's biggest upcoming dramas, including War And Peace and Dickensian, were dependent on co-production deals and outside investment.
"That puts more money on screen for the British public and helps take the best British content to global audiences," he said.
"But this model only works if BBC Worldwide is thriving. It is an indivisible part of the BBC.
"It is because of its special relationship with the BBC that it has scale. Because of this, that it takes British creativity to the world. Because of this, that it brings the benefits of globalisation back to the UK.
"Or to look at it through another lens, without BBC Worldwide, the licence fee would be £10 higher.
"That's why any proposal to carve out BBC Worldwide from the BBC doesn't make economic sense."
Lord Hall said the BBC must be leaner and more efficient but argued that a decline of the corporation would result in a void in British programming which would not be filled by upcoming international providers such as Netflix or Amazon.
He said it was not "isolationist or backward looking" to stress the importance of Britishness in programme making.
"The Britishness of British broadcasting is under challenge. It's obvious and measurable," he added.
"The Britishness of British broadcasting isn't something that just happens. Global markets won't take care of it - we have to."
He said the BBC should be unashamed about making money if it meant it could provide a better service to the public.
"We need to raise commercial income to supplement the licence fee so we can invest as much as possible in content for UK audiences," Mr Hall added.
The corporation has launched a consultation over plans to establish a new £400 million commercial company which would see about 2,000 staff who make its "crown jewel" shows such as EastEnders, Casualty and Strictly Come Dancing transferred to the private sector.
The new subsidiary, called BBC Studios, is designed to stem the tide of talent leaving the broadcaster for the commercial sector.
Referring to these proposals, Lord Hall said: " There are many questions, details and differences of opinion to be worked through.
"I want - and the teams want - to work with you to get these proposals right."
Lord Hall was speaking after Culture Secretary John Whittingdale told the convention on Wednesday night that there was "no prospect" of the BBC being abolished but insisted it must modernise.
Mr Whittingdale has already warned of cuts at the BBC, saying that the organisation should make "the same efficiency savings as we're asking every public body to do".
The stance has provoked a public debate, most notably with satirist and Thick Of It creator Armando Iannucci saying ministers should help promote the BBC to "capitalise financially" overseas.
The Department for Media, Culture and Sport has announced a review of how the BBC is regulated as part of the ongoing Royal Charter review, saying it was being launched in light of "bad mistakes" in recent years.
Mr Whittingdale also raised questions over the future of the BBC News At Ten, saying the broadcaster should explore whether it was "sensible" to broadcast its flagship news programme at the same time as ITV.
Asked about this after his speech, Lord Hall said the audiences for the 10pm bulletin were "extremely good", adding that the decision to move to that time-slot was made at a time when ITV often shifted the time of its bulletin.
"It has allowed BBC1 to run drama it could not have otherwise run," Lord Hall said.
He was also asked whether it was right to broadcast singing competition The Voice against ITV's X Factor and said competition had always existed between the two channels.