GT Advanced Technologies Inc. (NASDAQ: GTAT) (the “Company”) today announced the pricing of $205 million aggregate principal amount of its 3.00% Convertible Senior Notes due 2017. The Company has granted the underwriters an option to purchase up to an additional $15 million aggregate principal amount of the notes from the Company.

The notes will mature on October 1, 2017, unless repurchased or converted in accordance with their terms prior to such date, and will bear interest at a rate of 3.00% per year, payable semiannually in arrears on April 1 and October 1 of each year, beginning on April 1, 2013. The notes will be convertible, under certain circumstances, into cash, shares of the Company’s common stock, or a combination of both, at the Company’s election, at an initial conversion rate of 129.7185 shares of the Company’s common stock per $1,000 principal amount of notes, which is equivalent to an initial conversion price of approximately $7.71 per share of the Company’s common stock. The Company will not have the right to redeem the notes prior to maturity.

The Company has also entered into convertible note hedge transactions with certain financial institutions, some of which are affiliates of the underwriters (the “Option Counterparties”) , which are intended to reduce its exposure under the notes to future increases in the price of the Company’s common stock. The Company has also entered into separate warrant transactions with the Option Counterparties, and the warrants have an exercise price that is approximately 67.5% higher than the closing price per share of the Company’s common stock on September 24, 2012. The issuance of the warrants could have a dilutive effect on the Company’s common stock to the extent that the market price exceeds the exercise price of the warrants. If the underwriters exercise their option to purchase additional notes, the Company may enter into additional convertible note hedge transactions and additional warrant transactions with the Option Counterparties.

The Company estimates that the net proceeds of this offering will be $198.3 million (or $212.9 million if the underwriters’ option to purchase additional notes is exercised in full), after deducting the underwriters’ discounts and commissions and estimated offering expenses. The Company expects to use approximately $15.2 million of the net proceeds from the offering to pay the cost of the convertible note hedge transactions (after such cost is partially offset by the proceeds to the Company from the sale of the warrants in the warrant transactions). The Company intends to use the remainder of the net proceeds of the offering for general corporate purposes, which may include the acquisition of companies or businesses, repayment and refinancing of debt, working capital and capital expenditures.

In connection with the convertible note hedge transactions and the separate warrant transactions, the Option Counterparties (or their affiliates) that will be parties to those transactions have advised the Company that they expect to enter into various derivative transactions in the Company’s common stock, and may purchase and sell the Company’s common stock in secondary market transactions, concurrently with or shortly after the pricing of the notes. This activity could increase (or reduce the size of any decrease in) the market price of the Company’s common stock or the notes at that time. In addition, the Option Counterparties or affiliates thereof may modify their hedge positions by entering into or unwinding various derivatives with respect to the Company’s common stock and/or purchasing or selling the Company’s common stock or other securities of the Company in secondary market transactions following the pricing of the notes and prior to the expected maturity of the notes (and are likely to do so during any observation period related to a conversion of notes). This activity could also cause or avoid an increase or a decrease in the market price of the Company’s common stock.

This press release shall not constitute an offer to sell or a solicitation of an offer to buy these securities, nor shall there be any sale of these securities, in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state.

UBS Investment Bank, BofA Merrill Lynch and Credit Suisse will act as joint book-running managers for the offering. The issuer has filed a registration statement (including a base prospectus and related preliminary prospectus supplement) with the Securities and Exchange Commission, or SEC, for the offering. Before you invest, you should read the preliminary prospectus supplement, the accompanying prospectus and the other documents the issuer has filed with the SEC for more complete information about the issuer and the offering. You may get these documents for free by visiting EDGAR on the SEC web site at www.sec.gov. Alternatively, the issuer, the underwriters or any dealer participating in the offering will arrange to send you the preliminary prospectus supplement and the accompanying prospectus if you request them by contacting UBS Investment Bank, Attn: Prospectus Department, 299 Park Avenue, New York, NY 10171 or by calling (888) 827-7275, by contacting BofA Merrill Lynch, Attn: Prospectus Department, 222 Broadway, 7th Floor, New York, NY 10038, by calling (866) 500-5408 or by emailing dg.prospectus_requests@baml.com or by contacting Credit Suisse Securities (USA) LLC, Attn: Prospectus Department, One Madison Avenue, New York, NY 10010, by calling (800) 221-1037 or by emailing newyork.prospectus@credit-suisse.com.

About GT Advanced Technologies Inc.

GT Advanced Technologies Inc. is a global provider of polysilicon production technology, and sapphire and silicon crystalline growth systems and materials for the solar, LED and other specialty markets. The company's products and services allow its customers to optimize their manufacturing environments and lower their cost of ownership. For additional information please visit www.gtat.com.

Forward-Looking Statements

This press release contains forward-looking statements regarding our planned offer and sale of senior convertible notes and the use of the net proceeds from any such sale. We cannot be sure that we will complete the offering or, if we do, on what terms we will complete it.Forward-looking statements are based on current beliefs and expectations and are subject to inherent risks and uncertainties, including those discussed under the caption “Risk Factors” in the prospectus and prospectus supplement.In addition, management retains broad discretion with respect to the allocation of the net proceeds of this offering.The forward-looking statements speak only as of the date of this release, and GT Advanced Technologies Inc. is under no obligation to, and expressly disclaims any such obligation to, update or alter its forward-looking statements, whether as a result of new information, future events, or otherwise.