AIM-listed natural resources investment group Polo Resources announced it will increase its stake in Australian gold exploration company Blackham Resources.The group, which purchased a 4.2% stake in Blackham in March, will subscribe for 49% of the enlarged capital of Perfectus Management which in turn owns 15% of the Australian group. This will lift Polo's combined direct and indirect holding in Blackham to 11.85%.The company expects to pay AU$1m in cash and an additional AU$2m by way of issuing 7m new shares at a price of 15p per share to Perfectus. The firm can buy a further 49% of Perfectus within the next two years for AU$3m worth of shares at 15p, which if exercised, would up the group's stake in Blackham to 19.2%. Executive Chairman Michael Tang said: "Our increased interest in Blackham demonstrates our confidence in the potential of its gold exploration assets and of its management to generate strong shareholder returns."As of 09:36 the share price had risen 2.94% to 12.75p.WS