An announcement said Wellington joins Schroder Investment Management North America Inc., which has advised the $2-billion international small-capitalization fund since its inception in 1996.

Overseeing Wellington’s portion of the fund will be a four-person investment team led by Simon H. Thomas, who has worked on the firm’s international small-cap equity team since joining Wellington in 2002, the announcement said.

The team uses a bottom-up investment process to identify stocks whose prices do not reflect their long-term growth potential or are priced at a discount to their true value.

Wellington advises nearly $180 billion across 16 Vanguard mutual funds among its more than $530 billion in assets under management, according to the news release.