MELBOURNE, Australia--Macquarie Group Ltd., Australia's largest investment bank, forecast a slight rise in annual profit after a better-than-expected first six months and said it would tap a capital surplus to buy back up to 1 billion Australian dollars (US$766.1 million) of its shares. The modest improvement in guidance for the fiscal year came after a strong first-half from Macquarie's fund management and other annuity-style businesses, helped by an increase in performance fees, that offset weakness in its capital-markets facing operations. Macquarie, which also announced a shuffle for its finance chief and the appointment of former central bank Gov. Glenn Stevens to its board, said that while it expected its second-half profit would be lower than in the first half it now anticipated the full-year profit would slightly up on the year before. As recently as last month the bank had pointed to a full-year result broadly in line with the prior year's all-time high profit.