"This is an exciting time for Seven as we welcome James back to the company,"Seven chairman Kerry Stokes said in a statement.
The move comes as Seven's share price languishes at record lows of 38¢. Mr Worner was involved in a lengthy court battle afteran affair with his former executive assistant Amber Harrison.
"James has extensive experience in the industry with knowledge across media,advertising,sports administration,marketing and particularly sales. His passion and energy will reinvigorate the team. We look forward to the contribution he will make,"Mr Stokes said.
"Our industry is more dynamic today than ever,experiencing rapidly evolving market conditions which continue to present us with challenges and opportunities. 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 in a statement he was"delighted to be returning to Seven and I am excited about the opportunities that lie ahead to continue to build the business".
"The foundation of the business is a powerful combination of assets underpinned by outstanding content from Seven Studios,news and our partners in AFL,cricket,horse racing and the Olympic Games,"he said.
Mr Worner thanked the board and chairman for their"ongoing support and counsel"and said he resigned with mixed emotions to leave Seven after joining the business 25 years ago.