Former federal treasurer Peter Costello has been named as the new chairman of Channel 9, replacing David Haslingsden who will step down on March 1.

"I am delighted to take over the role of chairman," Mr Costello said in a statement.

"This is an exciting time of change in the media sector and NEC [Nine Entertainment Co] is now strongly positioned to take advantage of these developments."

He also praised the contributions made by Mr Haslingsden.

"I pay tribute to David for the leadership he has given the company since 2013," he said.

"His experience and understanding of the industry, and commitment to NEC have been invaluable throughout this period.

"The company is in an extremely strong financial position."

Mr Costello, who was treasurer under former prime minister John Howard, will continue as chair of the Board of Guardians of the Future fund.

He will also continue as a member of the international advisory board of the global insurer Allianz and chair of the Melbourne-based boutique advisory business ECG Financial.

Nine Entertainment Co reports fall in half-year profit

The appointment comes after the free-to-air and digital television company NEC reported a fall in its half-year profit.

In the six months to the end of December, the company had made $80 million after tax.

That was down from its profit of $88.8 million during the same period the year before.

Mr Haslingden said he was leaving the company in good health.

"The company has achieved a lot in that short time: going public, consolidating into a five-cap city network, renewing key cricket and NRL franchises, disposing of Nine Live, launching Stan and 9Now and transitioning to a balanced share register of leading Australian and International funds managers," he said in a statement.

"The time is right for me to move on from NEC, leaving the company with a new chief executive and a best-in-sector balance sheet; a modern content business ideally placed to embark upon the challenges of the next phase of sector evolution."

Channel 9 also announced the appointment of Elizabeth Gaines as a non-executive independent director, also from March 1.

Ms Gaines is a non-executive director of Fortescue Metals Group and Next DC, and a commissioner of Tourism Western Australia.

Nine trading 25pc below float price

Since relisting, Nine has found it tough going and was trading around 25 per cent below its float price of $2 a share.

Nine chief executive Hugh Marks said the result was solid in a challenging advertising market.

The overall metro free-to-air advertising market fell 0.4 per cent in the six months to December, while regional markets continued their sharp decline with revenues down another 6.6 per cent in the half.

Worryingly for Nine, its share of the metro revenue stream fell by 1 per cent to 38.2 per cent after several years of solid growth.

Nine eliminated its almost $500 million worth of debt with the sale of the Nine Live business and took another $23.5 million worth of costs out of the business.

The improved balance sheet allowed Nine to almost double its interim dividend to 8 cents a share.

At 3:25pm AEDT Nine Entertainment shares were up 5.2 per cent to $1.52.