Wilks Brothers said their plan will lower the company's total debt to below C$95 million ($70.92 million) through an exchange of debt for shares, with the group owning 60% of the reorganized company's equity.
The investor's latest step escalates a fierce battle for control of Canada's largest oilfield services provider after its market value slumped due to a collapse in drilling activity after this year's oil price rout, brought on by coronavirus-related lockdowns.
Up to Monday's close, Calfrac shares have plunged over 88% so far this year.
The group had earlier submitted two bids to take over Calfrac's U.S. operations in exchange for the debt they own, but the company's board rejected those proposals saying they "significantly undervalued" the unit and did not lower debt.
Instead, the board extended its support to a management-led plan for debt reduction.
Wilks brothers on Tuesday argued the management's plan only reduces debt to around C$286 million, "contains serious flaws" and leaves the business at a high risk of filing for bankruptcy in the near future.
The group currently holds nearly 20% of Calfrac's shares, more than half of its second-lien notes, and also owns ProFrac Services Ltd, a competitor of Calfrac in the United States.
(This story corrects to C$95 million from C$75 million in paragraph 2)
By Shariq Khan and Arundhati Sarkar
