MEG shares were up $2.94 or about 37 per cent at $10.97 in early trading on the Toronto Stock Exchange after going as high as $11.70.
Husky shares were down $1.63 or about seven per cent at $21.05.
The hostile offer is a combination of cash or shares worth $11 for each MEG share. The maximum cash available under the deal is capped at $1 billion and the maximum number of shares limited to 107 million.
Husky valued the transaction at $6.4 billion, including the assumption of $3.1 billion in debt.
MEG urged its shareholders to wait until its board has had a chance to review the offer and make a recommendation.
Husky says the proposal will be open for acceptance by MEG shareholders until Jan. 16.