The Botswana government has signed a new diamond sales agreement crucial to its economy with the De Beers mining company after seven years of negotiations.

Botswana's government on Tuesday signed a long-delayed 10-year diamonds sales agreement with Anglo American unit De Beers adding a possible extension period of five more years to the provisional pact.

Botswana's government and De Beers finalised a 10-year diamond sales agreement after a protracted negotiation period, Reuters reported.

As part of the deal, Botswana's share of diamonds from Debswana, a joint venture with De Beers, will rise from 25% to 50%.

De Beers and Botswana’s government will jointly fund a marketing campaign to resuscitate demand for natural diamonds.