Brookfield Infrastructure Partners on June 2 raised its hostile bid to buy Inter Pipeline Ltd. to CA$8.48 billion (US$7.02 billion), topping Pembina Pipeline Corp.'s CA$8.3 billion offer to buy the Canadian oil and gas transportation company.

The latest offer valued Inter at C$19.75 per share, C$3.25 above the investment firm's previous offer and 30 Canadian cents above Pembina's offer on June 1.

Brookfield's latest offer represents 4.4% premium to Inter's Tuesday's close, and comprises 74% cash as compared to zero in Pembina's offer.

Brookfield, the largest shareholder of Inter with a 9.75% stake according to Refinitiv IBES, said it was "disappointed by the seeming lack of fiduciary responsibility shown by the decision of IPL Board of Directors to support an inferior proposal by Pembina."

The firm added that it was taking the offer directly to Inter Pipeline's shareholders.

Inter Pipeline did not immediately respond to a Reuters request for comment.

On Tuesday, Inter Pipeline reiterated its recommendation, first made in March, that shareholders reject Brookfield's earlier bid, saying the offer significantly undervalued the company.

Brookfield had previously said it could raise the offer to as much as C$18.25 per share.

Pembina's U.S.-listed shares rose 1.2% to $31.71 in premarket trading.