CALGARY — A major shareholder of Canadian Pacific who wants to shake up management at the railway has brought his public campaign for change at the top of CP directly to Canadian investors.

Bill Ackman, head of the Pershing Square activist fund that holds a big stake in CP (TSX:CP), hosted a meeting Monday for hundreds of shareholders in Toronto.

Ackman said he believes current CEO Fred Green is the wrong man for the job, and instead endorsed handing the reins to former CN chief executive Hunter Harrison, whom he says has a far better track record.

"We think the board has chosen the wrong CEO," he told the audience of some 300 to 400 shareholders.

"The result is the worst railroad in North America."

Ackman said he believes the railroad suffers from a culture of inefficiency and needs operational change, adding that the CP board of directors has so far refused to interview his candidate.

In an onstage interview with Ackman Monday, Harrison said shareholders need to re-evaluate CPs strategy because the current operation of the railway "is the wrong place to put your energy."

Harrison said that means more than just change in the management ranks, which currently appear to be confused as to "what they really want to do and accomplish."

"You don't make change from the executive towers, and I've learned that the hard way."

Harrison' who oversaw a bug turnaround at CN before his retirement, said questions have been raised as to whether there's some "rust on his brain" after having been retired for two years. But the feisty 67-year-old challenged those who don't have faith, saying they could "hang me from Times Square" if he doesn't get the job done.

Harrison's emphasis is on what he calls precision scheduling -- timing everything from shipping times to shift changes -- to make CP more efficient.

He said he will focus on cost-cutting, downsizing and taking care of fewer assets as another way to bring down the company's operating ratio, a statistic that has been at the heart of criticism over CPs performance.

As for Ackman's role in the company, he said he's invested for the long haul , as long as his plan succeeds.

Ackman said he believes he'll be able to smooth things over with current board members. Despite his motive to overhaul its structure, Ackman said "this has not been a particularly acrimonious proxy battle."

Harrison said one of his first initiatives would be to "declare a war on bureaucracy" meaning he'd get rid of outside consultants and number crunchers in the first 100 days to streamline the operation.

Pershing Square is CP's (TSX:CP) biggest shareholder with a 14.2 per cent stake. Managing partner Bill Ackman will need to sell others on his plan if he's to successfully shake up the railway's board at its May annual meeting.

In addition to Pershing Square, the Top 10 list of Canadian Pacific's largest investors include big banks like RBC Global Asset Management, BMO Capital Markets and TD Asset Management, as well as Alberta's pension fund manager, AIMCo.

The Calgary-based railway has been widely held since the 2001 splitup of the old Canadian Pacific conglomerate into five separate hotel, shipping, rail, coal and energy companies.

The Tennessee-born Harrison, who will turn 68 this year, was once named Railroader of the Year by an industry trade publication and has a reputation for making trains run efficiently.

He ran the highly profitable Illinois Central railway in the 1990s and became a senior Canadian National executive when Canada's biggest railway acquired the Chicago-based operator a decade ago.

Some industry watchers believes paring operating costs will involve major job cuts at Canadian Pacific's workforce of nearly 17,000 people, asset sales or other streamlining moves to boost profits and the railway's stock market value.

Pershing Square believes Harrison can get Canadian Pacific's operating ratio from 81.3 in 2011 down to 65 in the next four years. Canadian Pacific says no railway has been able to achieve that steep a drop in that little time, and that Pershing Square's targets are unrealistic.

Canadian Pacific's top brass has also been on the road meeting shareholders to discuss what it's doing to lower its operating ratio to between 70 to 72 by the end of 2014.

It plans to grow revenue by maintaining "strong personal relationships" with its customers, which include coal miner Teck Resources Ltd. (TSX:TCK.B) and potash exporter Canpotex, among others, according to a slide show presentation made public last week.

It also has a multibillion-dollar capital investment program underway to improve its network and it says it's undertaking measures to improve efficiency and reliability.

Pershing Square's candidates for CP's board of directors includes two of its own representatives, Ackman and fellow fund partner Paul Hilal.

Also up for nomination are: Gary Colter, president of CRS Inc., a corporate restructuring and consulting firm; Rebecca MacDonald, executive director of energy marketer Just Energy Group Inc.; and Anthony Melman, CEO and chairman of Nevele Inc, a provider of strategic business and financial services.

Pershing Square is not at this point recommending which current Canadian Pacific directors should be replaced with its nominees.

Canadian Pacific's 15-member board includes some prominent names, including the CEO of energy giant Suncor Energy Inc., Rick George, and former deputy prime minister John Manley.

The rail company's chairman is John Cleghorn, once Canada's most powerful banker when he was CEO of the Royal Bank in the 1990s.