The company said Monday that the adjustments would support production expansions at its Canadian operations. The majority of output from those mines, a high-quality metallurgical coal, is exported to steelmakers in the Asia-Pacific basin.

"Western Coal's engine room of growth is in northeast British Columbia, where we continue to fuel regional economic activity through expansion of our operations, including the recently reopened Willow Creek mine," Western president and chief executive Keith Calder said.

"The amended agreement provides the stability that underpins Western's growth plans for further investments and job creation as we expand our production to over 6 million tonnes in the next two years.”

Ridley president George Dorsey noted that the long-term transaction also supported the facility’s expansion efforts.

Vancouver-headquartered Western Coal operates three mines in northeast British Columbia, four met and thermal mines in West Virginia, and both anthracite and metallurgical operations in south Wales in the UK.

Late last month, Arch Coal signed a five-year agreement for throughput capacity at the Prince Rupert facility as it expands shipment capabilities to the Pacific Rim markets.

Arch said it would gain 2Mt of coal capacity this year and up to 2.5Mt for 2012 through 2015.

RTI can load up to 12Mt of coal per annum, and expansion plans could increase that capacity up to 24Mtpa by 2015. Coal makes up more than 80% of the terminal’s total volume and Asia is its primary destination, with 8.3Mt of coal shipped last year.

"RTI's vision is to provide value to its parent company and expand its role as a leading trade gateway between North American and world markets," Dorsey said last month.

Ridley Terminals can handle Panamax as well as Cape-size vessel loadings of up to 280,000t.