UBS has hired one of Wall Street's most senior women to oversee $600 billion

UBS' asset-management arm has hired Suni Harford as its head of investments.

Harford will oversee about $600 billion and about 500 investment staffers from New York, according to a press release.

Harford is replacing Dawn Fitzpatrick, who left the bank earlier this year to join George Soros' family office as chief investment officer.

Harford joins UBS from Citigroup, where she previously worked for 24 years. She most recently was regional head of markets for North America.

Harford's hire is significant because few women hold executive investment roles within asset-management firms. At hedge funds, for instance, it is unusual to find women at the helm.