Air Canada is reporting a record adjusted net profit of $1.2 billion for 2015, but its stock plunged 12 per cent in Wednesday trading after a challenge to short-term investors from CEO Calin Rovinescu.

Adjusted earnings, which remove the effects of foreign exchange, fuel hedging contracts, employee benefits and other unusual items, are a closely watched metric at Air Canada.

The previous record, set in 2014, was $531 million.

But since then, Air Canada has increased its traffic, improved operating margins and seen much lower fuel costs.

For the fourth quarter, it posted a net loss of $116 million, widening from a $100-million loss a year earlier, despite an 8.6 per cent boost in traffic.

That was the bad news, but what seems to have sent investors to the exits was Air Canada's decision to stop reporting monthly traffic figures in favour of quarterly numbers.

In a conference call today, some investors demanded monthly reporting, but Rovinescu turned them down.

'See what the stock price does'

"To be very blunt, we're not running this company for the benefit of short-term investors from a day-to-day basis or from a month-to-month basis," he said.

"We'll see what the stock price does. If short-term investors don't like this, I can encourage them to leave. We're running this company for the benefit of our long-term stakeholders."

Air Canada stock fell 12 per cent to $7.39 at the close of trading.

For the full year, Air Canada had $13.87 billion of operating revenue, up $596 million or 22 per cent.

The company's adjusted net income for the full year equalled $4.18 per diluted share, including 40 cents in the fourth quarter, in line with analysts estimates.

Bombardier CSeries deal

Canada's biggest airline said it expects its cost per average seat mile, which excludes fuel expenses, to fall 2 per cent to 3 per cent this year,  if the value of the Canadian dollar remains the same.

Fuel prices have been falling, but the low loonie means Air Canada still faces exchange risk which it buys fuel and when it buys airplanes.

Today Air Canada announced a deal to buy up to 75 CSeries jets from troubled Bombardier.

In making the deal and agreeing to have the planes serviced in Quebec, it was able to get the province to drop a lawsuit over closure of the Aveos maintenance facility that once serviced its planes in Montreal.