CALGARY, Alberta (Reuters) - Shares of Suncor Energy Inc (>> Suncor Energy Inc.) jumped nearly 5 percent on Tuesday after Canada's largest oil and gas producer took steps to increase returns to shareholders and reported first-quarter earnings that surpassed expectations.

Suncor said late on Monday it would raise its quarterly dividend 54 percent to 20 Canadian cents per share from 13 cents and launch its repurchase plan to buy back C$2 billion ($1.97 billion) of its own shares, which will run from May 2 until September 19.

Suncor's shares were up C$1.39 to C$31.03 by late morning on the Toronto Stock Exchange. The shares had fallen 9.2 percent over the past 12 months.

Suncor is being pressed by investors to boost its flagging shares and increase a dividend that many considered to be miserly.

The dividend increase was "well above the 30 to 40 percent increase we were expecting as it tries to appease shareholders who have been aggressively calling for the company to accelerate returning some of its (free cash flow) generation to shareholders," Andrew Potter, an analyst with CIBC World Markets, wrote in a research note.

It also reported on Tuesday first-quarter operating profit of C$1.37 billion, or C$0.90 per share, compared with C$1.318 billion, or C$0.84 per share, in the year-prior period.

The results beat the average analyst forecasts of 75 Canadian cents per share, according to Thomson Reuters I/B/E/S.

Suncor is moving away from the traditional model for oil sands operations, where large-scale mines extract tar-like bitumen, which is then fed into upgraders and converted into synthetic light crude oil.

Earlier this year, on concerns that new shale-oil supplies would sate North American demand for light oil, the company canceled a new upgrader it was to share with French oil major Total SA (>> TOTAL). It will instead sell bitumen directly to refineries.

Suncor is still assessing whether it will go ahead with a new oil sands mine planned with Total, but said it can squeeze an additional 100,000 barrels per day of new production over the next four years from its existing operations through debottlenecking and small-scale projects at its mining and thermal operations.

"These include expansions that are already under way at our mine extraction facilities," Steve Williams, Suncor's chief executive, said on a conference call. "Other projects such as the expansion of Firebag (thermal oil sands project) to well beyond its 180,000 barrel per day capacity are still in the early stages of design but are moving steadily forward."

During the first quarter, the company produced 357,800 bpd from its oil sands operations.

(Reporting by Scott Haggett; Editing by Maureen Bavdek and Marguerita Choy)

By Scott Haggett

Stocks treated in this article : Suncor Energy Inc., TOTAL