BlackRock World Mining Trust had a good first quarter, outperforming the HSBC Global Mining Index with a 12% increase in its undiluted net asset value (NAV) per share. The HSBC Global Mining Index rose by 11% over the same period.Undiluted NAV per share (cum income) at the end of March stood at 736.56p, while on a capital only basis it stood at 736.09p. The share price's discount to NAV at the end of March stood at 15.6%, based on the capital only NAV per share.Short term borrowings at the end of the first quarter were £40.7m, and the trust's gearing was 3.0%.The trust's objective is to maximise total returns to shareholders through a global portfolio of mining and metal securities. Up to 10% of the assets may be invested in physical metals. The company is managed by Evy Hambro of BlackRock Investment Management (UK) Limited.