NATIXIS FUNDS

Supplement dated May 9, 2011 to the Natixis Statement of Additional Information (the “SAI”) dated May 1, 2011, as may be revised or supplemented from time to time, for the following funds:

Loomis Sayles Multi-Asset Real Return Fund

Effective immediately, the following paragraphs are added after the sub-section “Event-Linked Swaps” under the section “Investment Strategies and Risks”:

Exchange-Traded Notes

The Multi-Asset Real Return Fund may invest in exchange-traded notes (“ETNs”). ETNs are generally unsecured debt securities whose returns are linked to the performance of a particular market benchmark or strategy minus applicable fees. ETNs are traded on an exchange (e.g., the NYSE) during normal trading hours. However, investors can also hold the ETN until maturity. At maturity, the issuer pays to the investor a cash amount equal to the principal amount, adjusted to reflect the performance of the relevant benchmark or strategy factor(s).

ETNs generally do not make periodic coupon payments or provide principal protection. ETNs are subject to credit risk, and the value of the ETN may drop due to a downgrade in the issuer’s credit rating, notwithstanding the performance of the underlying market benchmark or strategy. The value of an ETN may also be influenced by time to maturity, level of supply and demand for the ETN, volatility and lack of liquidity in underlying assets, changes in the applicable interest rates, changes in the issuer’s credit rating and economic, legal, political or geographic events that affect the referenced underlying benchmark or strategy. When a Fund invests in ETNs, it will bear its proportionate share of any fees and expenses borne by the ETN. These fees and expenses generally reduce the return realized at maturity or upon redemption from an investment in an ETN; therefore, the value of the index underlying the ETN must increase in order for an investor in an ETN to receive at least the principal amount of the investment at maturity or upon redemption. A Fund’s decision to sell ETN holdings may be limited by the availability of a secondary market.

The market price and return of the ETN may not correspond with that of the underlying benchmark or strategy. The returns of some ETNs may be leveraged. Leveraged ETNs are subject to the same risk as other instruments that use leverage in any form. ETNs can, at times, be relatively illiquid, and thus they may be difficult to purchase or sell at an advantageous price. ETNs are also subject to tax risk. No assurance can be given that the IRS will accept, or a court will uphold, how the Fund or the Subsidiary characterizes and treats ETNs for tax purposes. Further, the IRS and Congress are considering proposals that would change the timing and character of income and gains from ETNs.