Channel Five chief executive Dawn Airey and the station's programme boss are to leave following media magnate Richard Desmond's takeover, it was announced today.
The channel will also shed between 60 and 80 jobs from its 300-strong workforce.
Ms Airey, director of programmes Richard Woolfe and managing director Mark White are among a number of senior executives who will leave in the coming months, staff were told this morning.
Mr Desmond's company Northern & Shell has also announced plans for £1.5 billion of investment in the channel over the next five years.
This is said to involve "a focus of resources on programme and content development".
Ms Airey will remain for several months and is leaving to take up a senior role at the RTL Group, Five's former owner.
Today's announcements are the first major moves since Mr Desmond's purchase of the channel last month from RTL in a £103.5 million deal.
Ms Airey will continue in her role for the time being "to facilitate the implementation of a cost-efficiency programme" which aims to return the firm to profitability.
She said today: "The day Five was sold, my job was done. I will be returning to the RTL Group but over the next few months will remain in post with a number of my senior colleagues to facilitate the integration of Five into Northern & Shell."
Other senior figures who will leave include director of strategy Charles Constable, and director of corporate affairs Sue Robertson will leave at the end of this month.
Managing director Mark White, director of finance David Hockley, director of legal Paul Chinnery, and head of HR Natasha Adams, are to go two months later.
Ms Airey added: "I want to thank Richard, Charles, Sue, Mark, David, Paul and Natasha for the dedication and commitment that they have shown Five and the support they have given me over the years. They have all made a significant contribution to leading Five towards a successful future.
"I love Five, its staff, its spirit and all we have achieved. I wish the channel, its team, Richard Desmond and Northern & Shell all the success they deserve."
Mr Desmond said: "Whilst I'm sorry to see Dawn move on, I'm thrilled that she'll be in the mix to contribute to the various exciting plans we have and oversee the acquisition and development of brilliant new content."
Northern & Shell said the changes and the investment plan - which it said would amount to £300 a year over the next five years - would "see the channel go toe-to-toe with the biggest players in the TV world".