Vale, the Brazilian mining group, was on Monday believed to have moved closer to acquiring Xstrata, its Anglo-Swiss rival, for as much as $90bn.

Market sources said Vale had strengthened its position in the negotiation with Xstrata after it secured bigger-than-expected increases in the prices paid by Japanese and South Korean steelmakers for its iron ore. Vale obtained price rises of at least 65 per cent, much more than the 30 per cent to 40 per cent expected by many observers.