Citi has promoted Catherine Weir, chief executive for the Europe, Middle East and Africa (EMEA) region to lead the new global family office group, reporting to Jane Fraser, global head of Citi Private Bank.
Replacing Weir as CEO of the EMEA business is Luigi Pigorini, global head of investment finance for the private bank, the memo said.
Citi declined to comment.
Family offices are mini financial institutions that manage the riches of single families, though many have started to diversify into taking on multiple clients.
The U.S. bank's push to formalise its offer of products and services to family offices around the world follows a strategic realignment of the private bank to target super-rich clients worth more than $25 million (16 million pounds), over the merely affluent.
Citi sold a controlling stake in its Smith Barney retail brokerage to Morgan Stanley
The Private Bank is smaller and more exclusive than Citi's wealth-management operation before the credit crisis.
Under the leadership of Fraser, who became CEO in mid 2009, it has moved to internationalise its client base away from a U.S. focus and repair the reputational damage suffered by the wealth-management industry during the credit crisis.
Citi Private Bank is now part of the institutional business, both because its clients are rich enough to need institutional-style services and because many of them are owners of companies that are corporate customers of the group.
The private bank has also embarked on an aggressive recruitment drive, luring from rivals bankers who specialise in servicing its targeted super-rich client base.
Following the reorganisation, Citi Private Bank is estimated to have between $100 billion (64 billion pounds) to $150 billion (97 billion pounds) in assets under management, putting it in the global top 25 wealth managers.
Both Weir and Pigorini will be based in London.
(Reporting by Chris Vellacott; Editing by Erica Billingham and Will Waterman)