NRW Holdings subsidiary Primero Group has secured a $40 million engineering, procurement and construction contract with Core Lithium to build a dense media separation plant for its Finniss project.

Core Lithium managing director Stephen Biggins said the EPC award represented the final stage of the Finniss study phase and the first step to unlocking the value of the Finniss lithium resource in the Northern Territory.

"We are excited to have Primero on board as an experienced and successful lithium EPC contractor and look forward to working together, delivering the DMS plant and creating an exciting opportunity for the people of the NT," he said.

"As we have stated to the market, construction of the Finniss project is on schedule to commence before the end of 2021, with Primero ready to hit the ground running immediately with initial work, in the lead-up to the commencement of process plant building activities in March next year."

Biggins said 2022 was shaping up to be a defining year for the company.

Under the scope of the EPC contract, Primero will provide project management, engineering and detailed design, equipment and materials procurement, DMS plant construction, quality assurance and construction verification, and ore commissioning on receipt of first ore.

Work is set to start once a final investment decision is made, with detailed engineering, procurement of long lead time equipment and securing structural steel to be done before the end of 2021.

On-site process plant construction activities will follow in March, with DMS plant commissioning and first concentrate production scheduled in the fourth quarter of 2022.

Primero managing director Cameron Henry said the Core Lithium project was another example of the quality of the company's processing knowledge.

"The working relationship with the Core team has been a four-year journey and we look forward to delivering on this contract and continuing the relationship with Core," he said.

NRW CEO Jules Pemberton said NRW continued to diversify its business streams into the future metals and energy space.