Exhibit 99.1

JOINT FILING AGREEMENT

The undersigned hereby agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned in accordance with the provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, and that all subsequent amendments to this statement on Schedule 13G may be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements.

Dated:  July 11, 2011

  GTH LLC     By:  /s/ Lance N. West                     Name:  Lance N. West Title:    Authorized Signatory   CENTERBRIDGE CAPITAL PARTNERS, L.P. By: Centerbridge Associates, L.P., its General Partner By: Centerbridge GP Investors, LLC, its General Partner   By:  /s/ Jeffrey H. Aronson            Name:  Jeffrey H. Aronson Title:    Authorized Signatory   CENTERBRIDGE CAPITAL PARTNERS STRATEGIC, L.P.   By: Centerbridge Associates, L.P., its General Partner By: Centerbridge GP Investors, LLC, its General Partner   By:  /s/ Jeffrey H. Aronson            Name:  Jeffrey H. Aronson Title:    Authorized Signatory       CENTERBRIDGE CAPITAL PARTNERS SBS, L.P.     By: Centerbridge Associates, L.P., its General Partner By: Centerbridge GP Investors, LLC, its General Partner   By:  /s/ Jeffrey H. Aronson               Name:  Jeffrey H. Aronson Title:    Authorized Signatory   CENTERBRIDGE CAPITAL PARTNERS AIV II, L.P.     By: Centerbridge Associates, L.P., its General Partner By: Centerbridge GP Investors, LLC, its General Partner   By:  /s/ Jeffrey H. Aronson           Name:  Jeffrey H. Aronson Title:    Authorized Signatory      

CENTERBRIDGE CAPITAL PARNTERS STRATEGIC AIV II, L.P.     By: Centerbridge Associates, L.P., its General Partner By: Centerbridge GP Investors, LLC, its General Partner   By:  /s/ Jeffrey H. Aronson                 Name:  Jeffrey H. Aronson Title:    Authorized Signatory     CENTERBRIDGE CAPITAL PARTNERS AIV V, L.P.     By: Centerbridge Associates, L.P., its General Partner By: Centerbridge GP Investors, LLC, its General Partner   By:  /s/ Jeffrey H. Aronson               Name:  Jeffrey Aronson Title:    Authorized Signatory   CENTERBRIDGE CAPITAL PARNTERS STRATEGIC AIV V, L.P.     By: Centerbridge Associates, L.P., its General Partner By: Centerbridge GP Investors, LLC, its General Partner   By:  /s/ Jeffrey H. Aronson Name:  Jeffrey Aronson Title:    Authorized Signatory     CENTERBRIDGE ASSOCIATES, L.P.     By: Centerbridge GP Investors, LLC, its General Partner   By:  /s/ Jeffrey H. Aronson            Name:  Jeffrey Aronson Title:    Authorized Signatory     CENTERBRIDGE GP INVESTORS, LLC     By:  /s/ Jeffrey H. Aronson          Name:  Jeffrey H. Aronson Title:    Authorized Signatory     JEFFREY H. ARONSON     /s/ Jeffrey H. Aronson                    MARK T. GALLOGLY     /s/ Mark T. Gallogly