TORONTO - The influential president and CEO of the Canada Pension Plan Investment Board is retiring after seven years at the helm of the multibillion-dollar fund that invests to pay future retirement benefits of 17 million Canadians.

The board announced Tuesday that David Denison will be replaced by Mark Wiseman, CPPIB's current executive vice-president of investments when he retires June 30.

Denison, 59, advised the board of directors in 2009 of his intention to retire in 2012, triggering a long-term succession plan.

The board said Denison has been critical to the pension fund's investment success -- growing assets to $153 billion -- but believes Wiseman is the ideal choice to continue that culture.

"David Denison's leadership has been exceptional in managing the assets of the CPP on behalf of 18 million Canadians while fostering a culture capable of undertaking the largest and most complex transactions in the world," Robert Astley, chairman of CPPIB's board of directors said in a statement.

"He has developed a talented team dedicated to CPPIB's purpose while placing an uncompromising premium on integrity," Astley said.

Since becoming president and CEO in 2005, Denison launched the fund's active investment strategy that will help pay out pensions even when payouts begin to outnumber contributions.

The board credits Denison with making investments across diverse asset categories in both public and private markets, which have "significantly contributed to the fund's growth."

The performance of CPP investment fund -- which invests the money not immediately required to pay pensioners -- is key to ensuring that future generations of Canadian have access to CPP payouts, even when the number of contributors declines in relation to pensioners.

Denison has 33 years of experience in the financial services sector and has held senior positions in investment, consulting and mutual fund businesses in Canada, the U.S. and Europe.

He was president at Fidelity Investments Canada just prior to being appointed to the CPPIB.

Denison was born in Gander, Newfoundland and raised in Montreal. He graduated from the University of Toronto with degrees in math and education and was a teacher for six years before beginning his business career.

Denison said he was delighted at the board's decision to choose Wiseman, who has been a public presence at the CPPIB and a frequent commenter on investment decisions.

"He has been an outstanding colleague and leader within CPPIB," Denison said in a statement.

"I can think of no one better suited and able to lead this great institution through its next stage of growth and evolution."

Wiseman, 41, is responsible for the fund's global investment program.

He joined CPPIB in 2005 following a senior position at the Ontario Teachers' Pension Plan.

He has also been an officer at Harrowston Inc., a Canadian merchant bank, and as a lawyer with Sullivan & Cromwell, practising in New York and Paris.

Wiseman holds a BA from Queen's University and a law degree and MBA from the University of Toronto.

"It is a distinct honour to have been selected to lead this institution and to succeed an extraordinary leader like David Denison," said Wiseman.

"I look forward to taking the helm at a time when CPPIB is playing an increasingly important role globally, investing in order to ensure the long-term growth and sustainability of the CPP Reserve Fund."

The sustainability of pension funds has been making headlines lately as the government tries to prepare for a looming pension crisis as baby boomers retire, drawing down funds in the system instead of contributing.

Canada's chief actuary has reviewed the fund's health and affirmed that it remains sustainable at the current contribution rate of 9.9 per cent for at least 75 years.

Contributions are expected to exceed benefit payouts until 2021, when the CPPIB investments will help to fund pensions.

The fund's assets are expected to see substantial growth in the next half century -- projected to surpass $1 trillion by 2050, according to the Chief Actuary's report.