MediaWorks chairman Rod McGeoch has come out swinging in defense of his embattled chief executive, who he says has had his contract extended.

Mark Weldon, the former Olympian and NZX chief executive turned wine-maker, has been under scrutiny amidst concern over ratings at TV3.

But today in a letter to staff, McGeoch told staff that Weldon was going nowhere.

"The references to Mark Weldon that have taken place in the last few days are well beyond what any reasonable person would see as a justifiable reaction to an environment of change and, in the Board's view, are totally unacceptable," the email to all staff states.

READ MORE: MediaWorks staff urged to boycott CEO Mark Weldon's Central Otago wine

"I also want to state to you all very clearly that Mark has the owner and board's full commitment and full support to lead the business through this period of change, and well beyond. While we had no intention of making a public announcement on this, it is, in this context, important to note that Mark has agreed with the Board and the Owner for a meaningful contact extension, which was recently signed."

A spokeswoman for MediaWorks declined to comment.

McGeoch's email also offered praise to staff for the changes being made in the company.

"We are aware of the challenges the organisation faces in adapting to a rapidly changing media market. However, genuine and significant progress has been made in the last year and most visibly in the last six months as the very clear strategy laid out has begun to be implemented, and as a board we are appreciative of this."