The deal, which is subject to regulatory and other approvals, is expected to complete in the last quarter of 2014.
It involves HSBC Private Bank (Suisse) transferring $12.5bn (£7.3bn, €9.2bn) of assets for clients in countries across Europe, Africa and Latin America.
This will more than halve the number of countries in which the Swiss business has customers, from 150 to around 70.
HSBC said in a statement that “it represents further progress in the execution of HSBC’s strategy” which has involved, since Stuart Gulliver was appointed chief executive in 2011, a worldwide focus on increasing profitability and reducing risk.
The strategic overhaul has seen it sell or otherwise get out of more than 50 businesses. In March last year, as he was unveiling the company's 2012 results, Gulliver said he wanted to find a further $1bn in annual savings in 2013.
Since then Europe’s biggest banks have faced escalating fines from regulators all over the world.
According to a recent briefing note from analysts at Credit Suisse, ten banks including HSBC, UBS and Societe Generale, have paid $37bn (€27bn, £22bn) to date, with a further $28bn already factored in, and a further $38bn not so far set aside.
