The combined profits for the world's top 10 wealth managers have swelled nearly 60% in the past two years to $22.9bn (€17bn), and the biggest of them - including the wealth operations of UBS, Merrill Lynch and Wachovia - are accounting for ever greater chunks of their parents' bottom lines.

An equity research report on wealth management, from Bear Stearns analysts Christopher Wheeler and Matthew Ingram, found that it is the fastest-growing sector in financial services.