TC Energy Corp. won’t sweetening its bid to buy out other unitholders of TC PipeLines LP, a U.S. master limited partnership it operates.

CALGARY—TC Energy Corp. says it has no intention of again sweetening its bid to buy out the other unitholders of TC PipeLines LP, a U.S. master limited partnership it operates, despite the vow of its largest nonaffiliated investor to vote against the transaction.

On Friday, Connecticut-based Energy Income Partners said it believes the offer of 0.7 common shares of TC Energy for each unit of TC PipeLines is inadequate and “significantly undervalues” its assets and growth potential.

The dissident unitholder says it owns more than 10 per cent of the partnership and has maintained a position in the company for nearly 15 years. TC Energy owns about 24 per cent of the units.

In its response, TC Energy says the exchange ratio represents a 20.8 per cent premium to the partnership’s closing price before the original offer as of Oct. 2.

The board of directors of the partnership’s general partner agreed to support the deal in December after TC Energy raised the ratio to 0.7 of a TC Energy share from the original 0.65 of a share.

A special meeting of unitholders to vote on the merger is set for Friday.

“We affirm the exchange ratio and we are confident that the meaningful transaction premium presents the best opportunity for (TC PipeLine’s) unitholders to maximize value,” said TC Energy CEO Francois Poirierin a statement Monday.

“TC Energy will not increase the exchange ratio or vary any of the terms of the merger.”