Petronas said PetroleumBrunei acquired a share of the production from its liquefied natural gas facility in the Pacific Northwest.
"As part of the proposed transaction, PetroleumBrunei has agreed to buy a 3 percent share of the LNG facility's [natural gas] production for a minimum of 20 years," the Malaysian company said.
Petronas acquired Canadian rival Progress Energy last year. The first gas from a LNG project in the Pacific Northwest is expected by 2018.
Petronas did not indicate the value of the transaction with PetroleumBrunei or the volume of LNG secured in the deal.
The Canadian government has courted Asian investors to its energy sector in an effort to diversify an export market that depends almost exclusively on the United States.
Both companies signed similar arrangements for exploration and development work in oil and natural gas fields in Malaysia and Brunei.