A worker arrives at the Jwaneng diamond mine,operated by Debswana, a joint venture between Anglo American unit De Beers and the Botswana government outside Gaborone,Botswana, in this picture taken November 25, 2015. REUTERS/Siphiwe Sibeko

GABORONE The World Bank on Thursday called on Botswana to make details of its large mining contracts with companies public to improve transparency in the diamond rich country’s business dealings.

Botswana earns 89 percent of its foreign exchange income and 30 percent of national revenues from mining, predominantly diamonds. It has various large-scale mining, sales and marketing contracts with Anglo American’s (AAL.L) diamond unit, De Beers.

World Bank Group consultant Nils Handler said in a report the government’s decision to keep the negotiation process around contracts for diamond mining and large integrated projects confidential was a cause for concern.

“A more open process, including published contracts, would assist Botswana in becoming a more transparent and accountable jurisdiction,” he said.

The government could not immediately be reached for comment.

De Beers and Botswana currently jointly own Debswana and DTC Botswana which are involved in the exploration, mining, manufacturing, and trading of diamonds.

(Writing by Tanisha Heiberg; Editing by James Macharia and Mark Potter)