PLS Group (ASX:PLS) started commissioning of its Mid-Stream Demonstration Plant in Western Australia, with the first product expected in the September quarter, according to a Friday filing with the Australian bourse.

The move follows the company securing up to AU$38.1 million in funding from the Australian Renewable Energy Agency to support the plant's operation, and entering an offtake agreement with Ningbo Ronbay New Energy Technology for lithium phosphate produced at the plant.

PLS Group also acquired Calix's (ASX:CXL) stake in the plant to gain full ownership and operational control of the facility, per the filing. Calix remains a technology partner in the project, which aims to test more efficient and lower-carbon processing pathways for hard-rock lithium.

Separately, PLS Group reported March quarter production of 232,400 tonnes and revenue of AU$567 million.

In the year-ago period, the company reported production of 125,000 tonnes and revenue of AU$150 million, an earlier filing showed.