Global investment banks in Japan may cut more than 3,000 positions in two or three years as risk-aversion and weak economic growth reduce earnings prospects in the country, Executive Search Partners Co. said Wednesday.

Overseas banks will shrink Japan payrolls to less than 20,000 from 23,724 as business wanes in stock underwriting, securities trading, real-estate finance and private equity, according to research conducted by the Tokyo-based consultancy firm.

Foreign financial firms have eliminated about 5,000 jobs in Japan over the past two years and are deepening head-count reductions as they question the country's growth prospects and deploy staff in China and elsewhere in Asia. China overtook Japan as the world's second-largest economy last year.