A deal which could see gas bills for households and businesses cut by almost 14% will go before Tynwald in November.
On Friday, Manx Gas announced an agreement over the proposed new tariff had been reached.
Policy and Reform Minister Ray Harmer confirmed the government had "agreed wording for a possible heads of terms".
Under the proposals, customers would receive an average refund of £93 in December, at a cost of £1.9m to the firm.
The new deal, which would see bills for domestic customers and small businesses cut by 13.7%, would see the company's profits capped at 6.99%, down from the current 9.99%.
Mr Harmer told Tynwald that Friday's announcement by the firm had been "more than a little presumptuous", as the voluntary agreement still had to be approved by the Council of Ministers before being put forward for debate by the parliament.
Although the issue was originally due to be put before Tynwald in October, Mr Harmer said the delay would allow time for "proper scrutiny" of the document, which was agreed on Thursday afternoon.
Manx Gas managing director David Cruddace said it was potentially "good news for customers".