"We expect a stormy 2008," Oliver Wyman said in its State of the Financial Services Industry report.
"While governments, central banks and regulators scramble to address the aftermath of the sub-prime fallout, several other crises are mounting."
Tumbling property prices - especially in the UK and Spain - a weakening dollar, a possible collapse in commodity prices, and a fall in Chinese and Indian stocks will "disrupt" the global economy, the report claimed.
Banks are already coming off one of the worst trading periods in memory, with shares across the industry plummeting 40pc in the past six months.
Oliver Wyman has estimated that financial services companies have already taken a $300bn hit on their sub-prime exposure.
It estimates that $1,300bn worth of sub-prime mortgages were written in total.
US banks will feel the pinch in particular, Oliver Wyman predicts. "North American financial services firms will have a tough year," it said. "Market uncertainty, combined with further write-downs and expected home-price and loan-volume declines, implies more squeezes on earnings. Banks most likely will have to increase loan-loss reserves."
Growth in Western Europe is likely to suffer in 2008, while Latin America has a positive outlook and "growth opportunities exist" in Singapore, Taiwan, Indonesia and Korea, according to the report.
The private equity industry is likely to grow in 2008, the consulting firm said.