The group this year undertook an assessment of its kaolin mining site in Cornwall and obtained an initial confirmation of the presence of lithium, Guillaume Delacroix, senior vice president in charge of performance minerals for EMEA, said during an investor presentation.

Imerys is pursuing exploration to establish the viability of mining lithium in the zone and views its kaolin operations in Cornwall's longstanding mining industry as an advantage should it decide to develop a project, he added.

Other companies have been prospecting for lithium in Cornwall as Britain, like the rest of Europe, seeks to reduce its reliance on imported minerals for electric vehicle batteries.

Imerys announced in late October a plan to produce around 34,000 tonnes of lithium hydroxide annually for at least 25 years from 2028, after finding a large deposit under a kaolin mine it operates in central France.

Chief Executive Officer Alessandro Dazza said he believed the lithium deposit in Cornwall represented "a quite significant amount" but less than detected at the company's Beauvoir site, north of Clermont-Ferrand, which was among the biggest found in Europe.

He reiterated that Imerys is keeping its options open about financing the Beauvoir lithium plan, for which it sees construction costs of about 1 billion euros ($1 billion).

A decision is expected next year on whether to take on a partner, with Imerys' preference to keep majority control, Dazza said.

The Beauvoir mine also has a significant amount of tantalum, which is used in electronic goods, as well as tin, which is partly used for semiconductors, and Imerys has started studying the possibility to extract these minerals that it does not currently produce, Dazza said.

Imerys announced financial targets for 2023-2025, including a goal to reach a core earnings margin of 18%-20% by 2025.

($1 = 0.9984 euros)

(Reporting by Gus Trompiz; Editing by Paul Simao)