While it is extending the amount of consultation, the commission is sticking to its original timetable to make final decisions by November 30, with new pricing from December 1.
The Ministry of Economic Development is understood to have been concerned that the commission's draft decision runs counter to the roll-out of the Government's ultra-fast broadband scheme. There are worries in the industry that the price regulation could put consumers off switching to ultra-fast fibre lines from copper services.
Among submitters who raised serious concerns on the commission's draft decision was Wellington funds manager Harbour Asset Management.
Its managing director Andrew Bascand warned the commission in writing that the proposed approach would add to negative sentiment among institutional investors, who see the commission as taking "extreme" initial positions and creating an unpredictable regulatory environment.
A further discussion paper is expected to be released in July, with submissions due in August, and a conference held in September.
Paul Harrison, head of equities at BT Asset Management, said in May that the commission's draft decision added "a whole lot of uncertainty into the mix".
Brokers had promoted Chorus' split from Telecom to international investors, who - as a result of the regulator's moves on copper pricing - may be wary about investing in New Zealand again, which would be unhelpful for the upcoming state-asset listings, Harrison said.