The battle to buy the last of Canada’s large pure-play oil sands producers may not be quite over yet.

Last week, MEG Energy Corp. MEG-T accepted a friendly $7-billion takeover offer from Cenovus Energy Inc. CVE-T two months after rejecting a hostile bid from Strathcona Resources Ltd. SCR-T that was worth nearly $6-billion. But late Thursday, Strathcona announced plans to acquire several hundred million dollars worth of MEG stock in order to vote against the Cenovus deal.

Strathcona already owns 9.2 per cent of MEG and is planning to increase that stake to 14.2 per cent. At current market value, acquiring an additional 5 per cent of MEG will cost Strathcona more than $350-million.

At least two-thirds of MEG investors will need to support the sale to Cenovus at an Oct. 9 meeting before the transaction can be completed. That means Strathcona will need to convince another 20 per cent of MEG shareholders to vote no in order to block the deal.

Adam Waterous, executive chair of Strathcona and head of the Waterous Energy Fund – which owns Strathcona – previously told The Globe that his offer for MEG is worth more than what Cenovus agreed to pay.

Cenovus is offering a mix of cash and stock for MEG, worth the equivalent of $27.25 a share and composed of 75-per-cent cash and 25-per-cent stock. The total deal value, including MEG’s existing debt, is $7.9-billion.

Although the Cenovus offer bests what the Strathcona offer was worth when it was made by roughly 17 per cent, the hostile bid has a much larger stock component, composed of 0.62 Strathcona shares and $4.10 an MEG share.

Because Strathcona’s shares have increased in value by more than 28 per cent since May, when the offer was first made, ATB Capital Markets said in an Aug. 22 report that the hostile bid is currently worth the equivalent of $28.17 an MEG share. That is nearly a full dollar per share more than what Cenovus has agreed to pay.

The increase in Cenovus’s share price after the deal was announced has since narrowed that gap, bringing the current value of the two offers closer together.

Both bids are backed by loans from some of Canada’s largest banks. Canadian Imperial Bank of Commerce and JP Morgan Chase & Co. have pledged $5.2-billion in loans to fund the Cenovus offer and Strathcona’s offer is based on borrowed money from Bank of Nova Scotia and Toronto-Dominion Bank.

Strathcona plans to continue engaging with MEG shareholders until the Sept. 15 deadline for its offer. In its statement on Thursday, Strathcona said the decision to buy more MEG shares was made after discussions with other MEG shareholders. Mr. Waterous did not respond to questions on Friday asking if other MEG shareholders voiced opposition to the Cenovus bid in those discussions.

Cenovus did not respond to a request for comment on Friday.

The Waterous Energy Fund has been on a buying spree in recent months. In March, WEF closed the final round of a third private equity fund with $1.4-billion of capital, earmarked for acquisitions in Alberta’s oil sands.

At the time, WEF said the money would go toward expanding Greenfire Resources Ltd., another oil sands producer with properties near those of both Cenovus and MEG. WEF had previously spent $450-million acquiring a 56-per-cent controlling stake in Greenfire.

With reports from Emma Graney and Andrew Willis