Form 3 Joint Filer Information



Name:    Columbia Capital Equity Partners III (QP), L.P.



Address:   201 North Union Street

   Suite 300

   Alexandria, VA  22314



Designated Filer: Columbia Capital III, LLC



Issuer & Ticker: SkyTerra Communications, Inc. (SKYT.OB)



Date of Event

Requiring Statement: 9/25/2006



Signature:   By: /s/ Donald A. Doering

   Chief Financial Officer







Name:    Columbia Capital Equity Partners III (Cayman), L.P.



Address:   201 North Union Street

   Suite 300

   Alexandria, VA  22314



Designated Filer: Columbia Capital III, LLC



Issuer & Ticker: SkyTerra Communications, Inc. (SKYT.OB)



Date of Event

Requiring Statement: 9/25/2006



Signature:   By: /s/ Donald A. Doering

   Chief Financial Officer







Name:    Columbia Capital Equity Partners III (AI), L.P.



Address:   201 North Union Street

   Suite 300

   Alexandria, VA  22314



Designated Filer: Columbia Capital III, LLC



Issuer & Ticker: SkyTerra Communications, Inc. (SKYT.OB)



Date of Event

Requiring Statement: 9/25/2006



Signature:   By: /s/ Donald A. Doering

   Chief Financial Officer









Name:    Columbia Capital Investors III, LLC



Address:   201 North Union Street

   Suite 300

   Alexandria, VA  22314



Designated Filer: Columbia Capital III, LLC



Issuer & Ticker: SkyTerra Communications, Inc. (SKYT.OB)



Date of Event

Requiring Statement: 9/25/2006



Signature:   By: /s/ Donald A. Doering

   Chief Financial Officer







Name:    Columbia Capital Equity Employee Investors III, LLC



Address:   201 North Union Street

   Suite 300

   Alexandria, VA  22314



Designated Filer: Columbia Capital III, LLC



Issuer & Ticker: SkyTerra Communications, Inc. (SKYT.OB)



Date of Event

Requiring Statement: 9/25/2006



Signature:   By: /s/ Donald A. Doering

   Chief Financial Officer







Name:    Columbia Capital Equity Partners III, L.P.



Address:   201 North Union Street

   Suite 300

   Alexandria, VA  22314



Designated Filer: Columbia Capital III, LLC



Issuer & Ticker: SkyTerra Communications, Inc. (SKYT.OB)



Date of Event

Requiring Statement: 9/25/2006



Signature:   By: /s/ Donald A. Doering

   Chief Financial Officer