Foster is credited with helping to scale Goldman's global commodities business, according to the memo signed by Dan Dees and Jim Esposito, co-head and global co-head of the investment banking division. The memo was seen by Reuters and verified by a bank spokeswoman.

While Foster's last role was in investment banking, she previously headed global commodities sales for Goldman's global markets division. She joined the bank in 1999 as a vice president in energy sales, and was named partner in 2006.

The bank has not yet named Foster's replacement.

(Reporting By Elizabeth Dilts Marshall; Editing by Will Dunham)