Amplitude Energy (ASX:AEL) signed a binding interim joint venture agreement with OG Energy's subsidiaries to develop the East Coast supply project, according to a Monday filing with the Australian bourse.

Under the terms, OG Energy will cover 50% of future project costs and reimburse Amplitude for 50% of historical costs, totaling about AU$25 million as of Jan. 31, the filing said. Reimbursement will be structured as a cost carry from the sale's completion.

Amplitude Energy plans to fund phase 1 of the project, estimated in the range of AU$240 million to AU$270 million, and phase 2, estimated at AU$140 million to AU$185 million, through existing cash, cash generation, bank debt, and potential financing options.

The agreement supports Amplitude's plan to drill three wells, aiming to deliver up to 90 terajoules per day of gas through the company's Athena Gas Plant in Victoria, with the first gas targeted by 2028, the filing said.

In addition, OG Energy agreed to acquire Mitsui E&P Australia's interests in the Otway Basin, including the Athena Gas Plant, subject to regulatory approval, the filing said.