(IDEX Online) - Alrosa is delaying its April trading session by a week to avoid excess stock accumulation.The Russian state-owned miner sold $372m of rough and polished in February, a modest seven per cent increase on last year.By contrast De Beers, its biggest rival, saw comparative sales rise more than 50 per cent.Earlier this month Alrosa announced a second extension to its existing three-year rough diamond supply contracts to help buyers respond to ongoing market uncertainties.Next month's trading session has been put back from 12 April to 19 April.Evgeny Agureev, the company's deputy CEO, said: "To maintain the market balance and avoid excessive stocks accumulation, clients should have ample time to process and sell the goods they have purchased earlier."This is why we decided to shift our forthcoming trading session by one week from the initial schedule."Alrosa says it is committed to allowing buyers to request only the goods they need in order to ensure the market equilibrium and optimal inventories' level.Pic shows rough sorting at Alrosa