News that first- quarter sales had doubled to £3.2m helped Big Yellow Group, which operates 20 storage centres in southern England, to rise 6p to 89 1/2p. It plans a 15% share buyback. Steel company Precoat International jumped 13p to 83 1/2p after agreeing the £6.2m sale of CSI, its Canadian offshoot, to Color Steels Holding Corp. Precoat proposes to return up to £5.9m to shareholders via a tender offer by broker KBC Peel Hunt at 95p.