The acquisition includes the two mines with a combined metallurgical coal production capacity of about 10 million tonnes per annum with total marketable reserves in excess of 135Mt, as well as the undeveloped Wards Well coal project.
The acquisition also includes port and rail agreements to support at least 10.5Mtpa through the Dalrymple Ba Coal Terminal facility at Hay Point and the North Queensland Export Terminal facility at Abbot Point.
Stanmore CEO Marcelo Matos said BMC's assets are in close proximity to Stanmore's and its MetRes JV's existing operating assets and there was potential for the combined group to benefit from shared infrastructure, corporate functions and coal blending opportunities.
"This is an exciting and transformative acquisition for Stanmore," he said.
"This transaction will see the company become one of the leading metallurgical coal producers globally and provide Stanmore with a portfolio of tier 1 assets, with a significantly increased reserves and resources base and assets with an expected mine life exceeding 25 years production, positioning the company for substantial cashflow generation and future growth opportunities.
"BHP have managed the BMC business competently and responsibly over the years, and as new custodians we look forward to integrating the BMC business into Stanmore with a continued focus on safety, and responsibly and sustainably producing high quality metallurgical coal products for our global customers."
BHP said it would continue to operate BMC until the deal was completed and would work closely with Stanmore to ensure a successful transition of ownership.
It will provide certain transitional services to Stanmore Resources for a short period of time after completion.
BHP president minerals Australia Edgar Basto said the transaction was consistent with BHP's plan, delivered value for its company and shareholders and gave certainty for BMC's workforce and the local community.
"As the world decarbonises, BHP is sharpening its focus on producing higher quality metallurgical coal sought after by global steelmakers to help increase efficiency and lower emissions," he said.
"South Walker Creek and Poitrel are well-run assets that have been an important part of our portfolio for many years and we are grateful for their contribution to BHP.
"Under this agreement, BMC will transition to Stanmore Resources, an ASX-listed company that has established relationships with Traditional Owners and strong engagement with their workforce and local communities.
"Stanmore Resources share our focus on safety performance and culture and support Australia's commitments under the Paris Agreement."
BHP said the review process for New South Wales Energy Coal was progressing, in line with the two-year timeframe announced in August 2020.
"BHP remains open to all options and continues consultation with relevant stakeholders," it said.
Stanmore and BMC's proforma production for the 12 months ending June 30 2021 was approximately 11Mt of saleable coal.
Steady state combined production is expected to be higher given production in FY21 was impacted by dragline maintenance at BMC and higher strip ratio at Isaac Plains before the Isaac Downs project started.
Stanmore is expecting greater production in 2022 from its recently started Isaac Downs project, with dragline operations commencing in March 2022, and the ramp up of production at MetRes' Millennium and Mavis mines.
The BMC portfolio includes significant infrastructure including an 8.4Mtpa coal handling and processing plant at South Walker Creek, the 9Mtpa Red Mountain coal handling and preparation plant in close proximity to Poitrel, two rail loops and train loading facilities, two Marion 8050 draglines, and a fleet of excavators, dozers and haul trucks.
"BMC metallurgical coal products are well established in the seaborne market and have high penetration in key global markets such as Japan, South Korea India, the largest growth driver of steel production and global met coal demand," Stanmore said.