European eyewear giant EssilorLuxottica said it had discovered fraudulent activity at a plant in Thailand, which could cost it $212 million.

The French-Italian company, which makes frames and lenses, has combined revenues of more than $16 billion, 140,000 employees and sales in more than 150 countries.

EssilorLuxottica was formed in 2018 following a merger between Italy's Luxottica – owner of Ray-Ban and Oakley glasses – and French lens manufacturer Essilor.

The group's shares fell by around one percent in early trading, following the announcement on Monday. 

The group added that the employees suspected of involvement in the Thailand fraud had been sacked. 

The company said its subsidiary, Essilor International, "filed complaints in Thailand and in other jurisdictions and mobilized all available internal and external resources to put an immediate end to these fraudulent activities and implement remedial actions."

"It is also carrying out comprehensive investigations and is taking all possible actions to seek to recover the misappropriated funds in order to mitigate the impact on the group," it added in a statement. 

The negative impact from the Thailand fraud would be recorded in its 2019 operating results, according to the company.