Leighton Contractors has taken a big step towards securing a stream of work on Rio Tinto’s $18 billion iron ore expansion in Western Australia’s Pilbara region.

The wholly owned Leighton Holdings subsidiary on Friday said it had inked five-year framework agreements for earthworks projects and structural, mechanical and piping (SMP) projects as part of the mining giant’s iron ore expansion.

Rio Tinto plans to exand its iron ore mining capacity to in the Pilbara 353 million tonnes per annum by 2015, up from about 230Mtpa this year.

“The framework agreements will deliver the earthworks contracts for the eastern stream of Rio Tinto’s expansion, which covers the Hope Downs 4 mine, Marandoo mine, Yandicoogina mine and Koodaideri mine,” Leighton said in a statement.

“Additionally, the framework agreements includes SMP work in the western stream of Rio Tinto’s expansion, which covers Brockman 4 mine phase two, Western Turner Syncline mine, Brockman 4 mine phase three and Nammuldi mine.”

Shares in Leighton were up 64 cents, or 2.53 per cent, at $25.94 at 1356 AEDT.