The company will initially supply cannabis products for the OCS's online but will later supply Ontario's private retailers, once the province implements an approved framework.
"As legalisation approaches in Canada, Ascent is pleased to have been chosen as a supplier to the provincial distribution bodies in two of Canada's largest markets," said Philip Campbell, chief executive.
"We look forward to introducing consumers to our adult-use products and continuing to expand our relationships with these two important purchasers."
Ascent also revealed that it had inked an initial small-scale supply agreement with the British Columbia Liquor Distribution Branch.
It is also in "advanced discussions" with other provincial liquor boards and emerging private retail operators.
In Canada, the firm is a licensed producer under the 'Access to Cannabis for Medical Purposes Regulations of Health Canada', with licences to grow cannabis.
At one of its cannabis operations, Flagship site - Agrima Botanicals, it is now harvesting weekly cannabis crops, it told investors last month.
Ascent requested a sales licence inspection from Health Canada (HC) for Agrima Botanicals in May and expects the inspection to be carried out in September this year.
Elsewhere, at the Agrima Labs campus, a 20,000 sq ft, production and manufacturing campus in Pitt Meadows, British Columbia, base-building construction is complete with the last remaining item to be installed, the level 10 vault, awaiting delivery.
Construction of phase 1 is expected to be fully completed by the end of the fourth quarter of 2018. Construction of phase 2, a further 20,000 sq ft, is anticipated to begin in the first quarter of 2019.
Meanwhile, Ascent's Agrima Meadows campus is a 600,000 sq ft greenhouse also located in Pitt Meadows, B.C.
The campus is in active review with HC. Construction and retrofitting will begin September 1 and is expected to be completed by the end of October, the company had said.
Shares on Monday rose 10.71% % at C$0.62.