The Commerce Commission wants to have its final review of Chorus' wholesale broadband charges wrapped up by December.
The regulator in November made a 50 per cent cut to one part of what Chorus charges companies like Vodafone or Orcon for wholesale broadband over copper internet lines, which the retail firms then on-sell to customers.
This reduction, together with other regulatory moves on price, is due to come into effect in December and the combined cut would see Chorus' monthly charge to retailers go down by 23 per cent.
When the cut was announced Chorus said it could hit its earnings by $142 million a year and put funding for the company's portion of the ultra-fast broadband project in jeopardy.
Last month Chorus and other industry players asked the commission for a final pricing principle review of the wholesale prices.