JOHANNESBURG, July 17 (Reuters) - South African workers at De Beers, the world's top diamond producer, have agreed to a pay rise of 9 percent and dropped a demand for more because the industry has been hit by the global crisis, their union said on Friday 17 June.

De Beers jewellery

The National Union of Mineworkers, South Africa's biggest mining union, had originally wanted 15 percent. That compared to the most recent inflation figure of 8 percent.

The deal comes as workers in the gold sector are gearing up for a national strike because discussions have failed to deliver the pay rise they seek. There have also been a rash of strikes and threats of industrial action in other industries.

Peter Bailey, chief negotiator of the union, said De Beers also agreed to a minimum wage of 5,000 rand ($614) per month.

Bailey said the union had to make a compromise, given that the diamond industry was one of the hardest hit by the global financial crisis.

"We agreed that De Beers should carry at least the inflationary burden ... but we need De Beers to survive because our members need to maintain their jobs and therefore had to make a significant compromise," he told Reuters.

De Beers is 45 percent owned by global miner Anglo American Plc (AAL.L).

(Reporting by Agnieszka Flak; Editing by Matthew Tostevin)