Before becoming involved with his grandfather's company, Occidental Petroleum, Hammer served in different roles at the New York City securities and investment banking firm Kidder, Peabody & Co.,[REF] which later was sold to PaineWebber, which ultimately merged with UBS AG in November 2000.
Since leaving Occidental, Hammer has worked with several companies, including OnVANTAGE, Inc. in 2000,[REF] which was later acquired by the company StarCite, Inc., and Avenue Entertainment Group as a member of the Board following an investment in the company by Hammer International in 1999 [REF].