MassMutual is an international financial services firm with nearly 13 million clients worldwide and over $505 billion in assets under management at year-end 2007. The company's marketing name is MassMutual Financial Group. As of 2006, following a series of mergers and acquisitions in Massachusetts, most notably Gillette, and FleetBoston Financial, MassMutual became the highest ranking firm on the Fortune 500 based in the state of Massachusetts. On December 18th, 2006, Stuart H. Reese, Chief Executive Officer and President of MassMutual, was named Chairman of MassMutual's Board of Directors.