The financial terms of the acquisition, which is expected to close in the fourth quarter, have not been disclosed.
Currently the business manages around $1.4bn in assets for high net worth families, endowments and foundations.
CIBC, through its retail and business banking, wealth management and wholesale banking businesses, provides a full range of financial products and services to almost 11m individual, small business, commercial, corporate and institutional clients in Canada and around the world.
Sun Life has held a majority stake in McLean Budden since 1997 and has acquired the remaining 32.4% minority stake in the investment firm in September 2011 for $144m.
McLean Budden, which has offices in Toronto, Montreal and Vancouver, manages $32bn in assets for mutual fund clients and others in addition to its private wealth management business.
Source: Private Banker International