Shareholders of Petro-Canada and Suncor Energy Inc. both approved a plan Thursday to merge under the Suncor name.

Petro-Canada investors approved the deal with a 96 per cent favourable vote at a company meeting in Calgary. Suncor shareholders, at a separate meeting in Calgary, were 98 per cent in favour.

Investors greeted the news enthusiastically. In TSX trading, Suncor stock jumped $1.76 or 4.9 per cent to $37.50, while Petro-Canada was up 4.8 per cent or $2.15 to $47.15.

Suncor shares are up $6.60 since the last day before the deal was announced March 23. Petro-Canada shares have jumped $17.40.

Suncor CEO Rick George told shareholders that "the new Suncor will look like the Suncor you know today," and "will remain a formidable player in the oilsands after it takes on Petro-Canada's assets."

Both George and Petro-Canada chief executive Ron Brenneman emphasized the benefits of being huge.

The merged company will be "able to compete with global supermajors," George told shareholders.

Brenneman said the company "will have a commanding presence as Canada's largest energy company and the fifth largest in North America," and will be "large enough to compete in the top tier of global energy companies."

The marriage of the two heavyweights was announced. Petro-Canada equity holders receive 1.28 shares in the new company for each Petro-Canada share, resulting in existing investors getting a 40 per cent piece of the merged entity. Suncor shareholders, who will get one share in the merged company for each Suncor share, will own the remaining 60 per cent of the new firm.

The new company will be one of the five largest in North America, and the second-largest firm trading on the Toronto Stock Exchange, trailing only Royal Bank.

When the deal was announced, George said the combination would make for a more efficient player in Canada's oil patch, which will insulate the new Canadian firm from potential foreign takeovers.

Montreal's Letko Brosseau & Associates, a comparatively small investor in Petro-Canada, has come out against the deal. Letko Brosseau claimed the transaction undervalues Petro-Canada and overvalues Suncor.

The deal must still be approved by regulators.