Debswana Diamond Company's sales of rough diamonds fell 25.1% in 2023, data released by Botswana's central bank late on Thursday showed, as an economic slowdown hit demand for luxury items in the U.S. and China and competition from lab-grown gems increased.

Debswana, equally owned by Botswana and Anglo American Plc's De Beers, sells 75% of its output to De Beers with the balance taken up by state-owned Okavango Diamond Company (ODC).

The central bank said Debswana sold diamonds worth $3.44 billion in 2023 from $4.59 billion registered in 2022, a year in which the joint venture made record sales.

Debswana's production in 2023 was up 2% to 24.7 million carats and the company has said it would cut production this year to match market conditions.

In recent months major industry players have taken measures to ease a supply glut, with India - which cuts and polishes 90% of the world's rough diamonds - implementing a two-month import pause, while ODC cancelled its November and December auctions.

Debswana senior corporate affairs manager Matshidiso Kamona told Reuters in January that the company would trim output in view of the reduced demand for rough diamonds in the global market but did not reveal the production target for 2024.

Botswana and De Beers in June last year agreed a new 10-year diamond sales agreement, which will see ODC's share of Debswana output rise to 30%, before rising gradually to 50% by the end of the new contract. (Reporting by Brian Benza, Editing by Bhargav Acharya and Elaine Hardcastle)