The contracts have a combined value of A$100 million.
The contract with Mach Energy to operate and maintain the Mount Pleasant site at Muswellbrook will generate revenue to Sedgman of approximately $75 million over three years.
The contract with QCoal to operate and maintain the Byerwen site at Glenden will generate revenue to Sedgman of approximately $25 million over one year.
CIMIC CEO Michael Wright said Sedgman had a strong track record of reliably operating and maintaining CHPPs, and these further contract wins highlight the company's strength in end to end mineral processing solutions.
Sedgman managing director Grant Fraser said Sedgman's strong working relationship with QCoal had developed over many years.
"We have been closely involved throughout the Byerwen project from the engineering, procurement and construction of the stockpile, train load-out and CHPP," he said.
"We are pleased to be completing the cycle by operating the plant.
"At Mount Pleasant we are building on CIMIC Group's long established partnership with Mach Energy and drawing on our relationship with Thiess, also a member of CIMIC Group, to deliver a seamless service that will maximise the value from the site."
The Mount Pleasant site will start operations towards the end of 2018. The Byerwen CHPP is now being commissioned.
Shares in CIMIC dropped 0.2% today to $46.77.