Tim Worner’s controversial six year run as Seven West Media chief’s executive has come to a sudden halt after he resigned with immediate effect.

“All parties agree now is the time for change,” chairman Kerry Stokes said in a statement.

The news of Mr Worner’s abrupt departure saw Seven West shares lift 12 per cent from Thursday’s all-time low 37.5 cents.

At 11.30am, the share price was 42 cents.

Mr Worner had been with Seven for 25 years and at the helm since 2013, a period that included a legal battle after a two-year affair with his former executive assistant was made public in 2016.

Last year Mr Worner was an architect of Seven’s high-profile grab of cricket from the Nine network.

Mr Worner with Cricket Australia CEO James Sutherland and Fox Sports’ Patrick Delaney at the cricket media rights announcement in April 2018. Photo: Getty

The network paid $450 million over six years to broadcast all home Test matches and 43 Big Bash League games.

“It’s with mixed emotion that I tender my resignation, however Seven – a company I love – is a very different company now from the one I joined 25 years ago,” Mr Worner said.

“It’s changed faster than ever in these last few years.”

Mr Worner’s replacement as CEO and managing director is James Warburton.

A previous chief digital and sales officer at Seven Media Group, Mr Warburton had a short stint as the Ten Network’s CEO in 2012 before becoming CEO of V8 Supercars then the boss of APN Outdoor.

James Warburton at the 2014 Australian Grand Prix. Photo: AAP

He quit that role last year when the company was taken over by global ad behemoth JC Decaux.

“We are fortunate that James was available to commence immediately,” Mr Stokes said.

Mr Warburton will reportedly be paid a basic $1.35 million salary, less than the $2.44 million in fixed remuneration paid to Mr Worner, according to Seven West’s 2018 annual report.

But Mr Warburton will have the opportunity to earn short-term bonuses of up to $2 million plus additional long-term bonuses.

In an email to Seven staff, Mr Stokes thanked Mr Worner “for his hard work” and said he had been a ‘tireless leader” at Seven.

But Mr Stokes said “rapidly evolving market conditions” continued to present the media industry with challenges.

“In reviewing the requirements for the company, the board has been considering the right mix of skills and experience required to take advantage of opportunities and accelerate into its next phase of growth.”

Mr Warburton said he is “delighted” to be returning to Seven, and “I am excited about the opportunities that lie ahead to continue to build the business.”

Amber Harrison in an undated photo. Photo: AAP

In 2017 an investigation cleared Mr Worner of explosive misconduct allegations made by a former employee with whom he had an affair.

His extra-marital relationship with his former executive assistant Amber Harrison became public knowledge when Ms Harrison contacted numerous media outlets with details of the affair.

She alleged she had been treated vindictively by Seven.

The independent review of allegations of credit card misuse, drug use and vindictive behaviour made by Ms Harrison concluded the claims were not supported.

Seven West’s board said there were no grounds to take any further disciplinary action against Mr Worner, beyond that which was taken in 2014 when the company became aware of his affair with then-employee Ms Harrison.