Lion Nathan has one month to complete the sale of the shares, which must be to a party or parties independent of the brewer.
The standing committee said it was essential that there be no contract, arrangement or understanding in place
by which Lion Nathan has any form of continuing entitlement to or interest in the shares sold.
"However, provided it does not have any such contract, arrangement or understanding in place at the time of transfer, Lion Nathan is free at any subsequent time to purchase Montana shares from any transferree of shares which are sold pursuant to this Ruling," the committee said.
The reduction of Lion's holding in Montana to 43 per cent will re-open the battle for control of New Zealand's largest wine-producing company.
British drinks company Allied Domecq, which holds 27 per cent, wants full control of Montana.
Allied, which initially brought the complaint against Lion’s February share purchase, had asked the committee to force Lion to sell all its holding in Montana.
Lion Nathan argued that only 9.9 per cent of Montana shares were caught in what it said was a "technical breach" of listing rules.
Full text:
Montana Standing Committee Decision
Feature: Montana takeover