IXIS ASSET MANAGEMENT ADVISORS, L.P. 399 Boylston Street Boston, MA 02116 July 1, 2005 IXIS Advisor Funds Trust I IXIS U.S. Diversified Portfolio 399 Boylston Street Boston, MA 02116 Attn: Michael C. Kardok, Treasurer Re: IXIS U.S. Diversified...