(IDEX Online) - De Beers has reportedly ditched around 10 of its 80 Sight holders as it seeks to exert more control over diamond pricing.It has also introduced new contracts dividing buyers into three categories - dealers, manufacturers and integrated retailers - as it embarks on a huge and much-heralded shake-up of the way it sells rough.The UK-based miner aims to put its diamonds into the hands of those who will add most value in a bid to strengthen the pipeline and eliminate inefficiencies.It wants fewer companies specializing in each category of diamond, so they can better weather storms such as the global pandemic, and maintain control over prices.Some international buyers will reportedly have to switch manufacturing to countries where diamonds are mined - rather than India - to retain their Sight holder status. The company contacted its Sight holders on Wednesday to tell them about the changes, sources told the Bloomberg news website.