TORONTO — An acrimonious takeover battle between two Canadian marijuana companies was in the regulatory spotlight Wednesday at a joint hearing involving the Saskatchewan and Ontario securities commissions.

Lawyers for both provincial regulators argued that Aurora Cannabis' (ACB.TO) request to lessen the consideration period for its all-stock offer be rejected but that CanniMed Therapeutics shareholders' rights plan to push back against its suitor be removed.

Kate McGrann, a lawyer representing staff at both the Ontario Securities Commission and the Financial and Consumer Affairs Authority of Saskatchewan, also told commissioners at the joint hearing that Aurora should be able to buy up to five per cent of CanniMed's (CMED.TO) outstanding shares on the open market.

Wednesday's hearing in Toronto kicking off the joint proceedings comes roughly one month after Aurora launched an all-stock, unsolicited bid to acquire Saskatoon-based CanniMed, one of the first licensed marijuana producers in Canada, after both companies called on regulators to intervene.

CanniMed has said that Aurora's offer is inferior to its own proposed acquisition of the Tragically Hip-backed Newstrike Resources (HIP.V), and launched a shareholders' rights plan to push back.

CanniMed has alleged that Edmonton-based Aurora worked jointly with some of its shareholders and Aurora has disputed this, while launching a dissident circular in a bid to thwart the Newstrike acquisition.