(GTT) Announces Pricing of Public Offering of Common Stock

GTT Communications, Inc. (“GTT” or the “Company”) (NYSE MKT: GTT) announced today the pricing of a public offering of 3,000,000 shares of common stock at a purchase price of $7.75 per share. The net proceeds to GTT from this offering are expected to be approximately $21.5 million, after deducting underwriting discounts and other estimated offering expenses payable by GTT. GTT has also granted the underwriters an option to purchase up to 450,000 additional shares of common stock to cover over-allotments, if any. The offering is expected to close on May 28, 2014, subject to customary closing conditions. GTT will use the net proceeds from this offering of common stock for general corporate purposes.

In connection with the offering William Blair & Company, L.L.C. acted as lead book-running manager. Craig-Hallum Capital Group LLC and Pacific Crest Securities LLC acted as joint book-running managers and Drexel Hamilton, LLC acted as Co-Manager.

A shelf registration statement relating to the offering of the common stock has previously been filed with the U.S. Securities and Exchange Commission (“SEC”) and has become effective. The offering is being made only by means of a prospectus supplement and accompanying prospectus, forming a part of the effective registration statement. Before investing, you should read the prospectus supplement and the accompanying prospectus for information about GTT and this offering. A prospectus supplement relating to the offering will be filed with the SEC and will be available on the SEC’s website at http://www.sec.gov. Alternatively, copies of the prospectus and prospectus supplement, when available, may be obtained by contacting William Blair & Company, L.L.C. at 222 West Adams Street, Chicago, IL 60606, Attention: Prospectus Department, by telephone at (800) 621-0687, or by email at prospectus@williamblair.com; by contacting Craig-Hallum Capital Group LLC at 222 South Ninth Street, Suite 350, Minneapolis, MN 55402, Attention: Prospectus Department, or by telephone at (612) 334-6300; or by contacting Pacific Crest Securities LLC at 111 South West Fifth Avenue, 42^nd Floor, Portland, OR 97204, or by telephone at (503) 248-0721, or by email at Prospectusrequests@pacific-crest.com.

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

Cautionary Statement Regarding Forward-Looking Statements:

Some of the statements contained in this press release might be considered forward-looking statements. These statements identify prospective information. Forward-looking statements are based on information available at the time and/or management’s good faith belief with respect to future events, and are subject to risks and uncertainties that could cause actual performance or results to differ materially from those expressed in the statements. These forward-looking statements are subject to a number of factors that may cause actual results to differ materially from the expectations described. Additional information about the factors that may adversely affect these forward-looking statements is contained in the Company’s reports and filings with the Securities and Exchange Commission. The Company assumes no obligation to update forward-looking statements to reflect actual results, changes in assumptions or changes in other factors affecting forward-looking information except to the extent required by applicable securities laws.