RATINGS RATIONALE

"The B3 CFR reflects the financial distress in MEMC's solar operations, which we expect will continue to burn cash for the near term due working capital demands and a more challenging financing environment", noted Terry Dennehy, Senior Analyst at Moody's Investors Services. The ratings also reflect our concerns that MEMC's efforts to reduce the cost base of the solar operations may prove insufficient to reach operating breakeven. Nevertheless, we expect that MEMC will receive cash proceeds in excess of $180 million from the sale of four European projects during the second quarter, which should provide MEMC the cash buffer needed to cover MEMC's restructuring charges and the working capital demands of the solar operations.

The Caa1 rating of the Senior Notes due 2019 ("Notes"), which are unsecured, reflects the effective subordination of the Notes to MEMC's $400 million Corporate Credit Facility, which is secured by a lien on all domestic assets.

The revision to SGL-3 reflects the expectation of cash inflow from the near term sale of certain European projects and at least $200 million of cash and access to the corporate revolver.

The stable outlook reflects our expectation that the pace of cash burn will moderate over the near term and turn solidly positive by the second half of 2012 as MEMC better manages the pace of construction in the solar operations and the semiconductor materials business becomes cash generative, and that there will be no further delays in selling the European projects.

The rating could be upgraded if MEMC's restructuring efforts prove successful, and the solar operations become cash generative, such that we believe that the ratio of free cash flow (FCF) to recourse debt (Moody's standard adjustments) will improve to the mid-single digits on a sustained basis.

The rating could be downgraded if there are delays in selling the European projects or we believe that the semiconductor segment recovery will be delayed. There could be a downgrade if we believe that the pace of cash burn will increase due to declining solar project margins, an increase in the pace of solar project construction, or if we believe that the solar operations' trade creditors will cease to offer trade credit, requiring cash payment in advance.

MEMC, based in St. Peters, Missouri, is a supplier of polysilicon semiconductor wafers to semiconductor foundries and integrated device manufacturers. MEMC also develops, constructs, and operates solar energy power projects through its SunEdison LLC subsidiary.

Downgrades:

..Issuer: MEMC Electronic Materials, Inc.

.... Probability of Default Rating, Downgraded to B3 from B2

.... Corporate Family Rating, Downgraded to B3 from B2

....Senior Unsecured Regular Bond/Debenture, Downgraded to Caa1 from B3

Upgrades:

..Issuer: MEMC Electronic Materials, Inc.

.... Speculative Grade Liquidity Rating, Upgraded to SGL-3 from SGL-4

Outlook Actions:

..Issuer: MEMC Electronic Materials, Inc.

....Outlook, Changed To Stable From Rating Under Review

The principal methodology used in rating MEMC was the Global Semiconductor Industry Methodology published in November 2009. Other methodologies used include Loss Given Default for Speculative Grade Issuers in the US, Canada, and EMEA, published in June 2009. Please see the Credit Policy page on www.moodys.com for a copy of these methodologies.

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The Global Scale Credit Ratings on this press release that are issued by one of Moody's affiliates outside the EU are endorsed by Moody's Investors Service Ltd., One Canada Square, Canary Wharf, London E 14 5FA, UK, in accordance with Art.4 paragraph 3 of the Regulation (EC) No 1060/2009 on Credit Rating Agencies. Further information on the EU endorsement status and on the Moody's office that has issued a particular Credit Rating is available on www.moodys.com.

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Terrence Dennehy Vice President - Senior Analyst Corporate Finance Group Moody'sInvestors Service, Inc.250 Greenwich StreetNew York, NY 10007 U.S.A. JOURNALISTS: 212-553-0376 SUBSCRIBERS: 212-553-1653Robert Jankowitz Associate Managing Director Corporate Finance Group JOURNALISTS: 212-553-0376 SUBSCRIBERS: 212-553-1653 Releasing Office: Moody's Investors Service, Inc.250 Greenwich StreetNew York, NY 10007 U.S.A. JOURNALISTS: 212-553-0376 SUBSCRIBERS: 212-553-1653(C) 2012 Moody's Investors Service, Inc. and/or its licensors and affiliates (collectively, "MOODY'S"). All rights reserved.

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