LONDON - Sigma Lithium's chief executive won't sell the miner at current lithium price levels and is concentrating on its near-term expansion plans, she told Reuters in an interview.

The Vancouver-based company, whose main business is a hard rock lithium project at Brazil's Grota do Cirilo, started scouting for potential buyers about a year ago. Since then, prices for lithium, a metal key for electric vehicle batteries, have been pressured by slower than expected EV adoption worldwide along with overproduction in China.

CEO Ana Cabral-Gardner said her focus was now on expanding operations.

"At these prices, we are not selling," she said.

"I am building a business, so I'm doubling capacity," she added.

Cabral-Gardner said last July that adviser Bank of America BAC.N had been holding meetings for several months with parties interested in acquiring Sigma, and the company later said it had received proposals from the energy, auto, batteries and lithium refining industries.

As well as lower prices, Sigma has weathered a number of executive shake-ups, including the firing early last year of former co-CEO Calvyn Gardner, whom Cabral-Gardner is divorcing, and a series of lawsuits in Brazil and the United States.

Cabral-Gardner said Bank of America was still leading a strategic review of the company, but she declined to give details.

"We started a strategic review, and we were like, okay, let's see if it makes any sense to do anything," she said. "It was unfortunate we did it against massive headwinds of this price."

In the meantime, she said Sigma was aiming to double in size by next year.

The company said this week it plans to increase production to 520,000 metric tons per year by 2025 from 270 000 metric tons currently, spending $100 million to add a second production line at its Greentech Industrial Plant in Brazil.

Brazil, which heavily depends on biofuels, exports most of its lithium.

The company's shares rose on news of the plan to raise output.

Sigma agreed in 2021 to supply lithium to LG Energy Solution, although last month the South Korean company initiated arbitration over what it deemed breaches of the deal. Sigma has denied the allegations. It also inked a supply deal last year with commodity trader Glencore.