The move is a part of Amas Bank's growth strategy to expand its presence in the Indian capital markets, the bank said in a statement. Amas declined to comment on the cost of the acquisition, when contacted by WealthBriefing.

"This investment is part of our renewed India focus and reinforces the strategy of the bank to advise corporations and investors between Europe and India, from our Swiss base. This will reinforce the capabilities of Amas Bank to offer Indian capital market services to its clients and build access to wealth management and corporate advisory services onshore," Ivan Schouker, chief executive of Amas Bank, said in a statement.

Paterson is one of India’s oldest stock-broking firms and a founding member of the Madras Stock Exchange. The company focuses on stock-broking, derivatives trading, portfolio and wealth management, NRI services, investment banking and allied financial services. It is also a member of the National Stock Exchange and Bombay Stock Exchange.

Already serving some companies of the Hinduja Group, Paterson entered acquisition talks with Amas Bank early this year. The terms were agreed in July. The deal then received the approval of the NSE and BSE.

"With the backing of the Hinduja Group, we are now in a position to expand our reach and accelerate our growth," said Amarnath Maitreyan, chief executive of Paterson.

Founded in 1978 as a finance company, Amas Bank was granted a banking licence in 1994. It is supervised and regulated by the Swiss Federal Banking Commission.

The bank, which is headquartered in Geneva, has a network that includes offices in Zurich, Lucerne, Basle and St Margrethen in Switzerland. It also has offices in London, Paris, New York and Mauritius.

In September, Amas set up a Gulf base in the Dubai International Finance Centre, as part of its efforts to respond to clients' needs in the Middle East and North Africa region.