There's a joining of forces upcoming — GHL Acquisition Corp. [AMEX: GHQ] and Iridium Holdings LLC have signed a definitive agreement to combine their resources. The proceeds of the transaction will enable Iridium to be debt free and well positioned to develop its nexgen satellite constellation, “Iridium NEXT.” GHL Acquisition is the special purpose acquisition company sponsored by Greenhill & Co., Inc. [NYSE:GHL], which raised approximately US$400 million of gross proceeds earlier this year, and is approximately 17.5 percent owned by Greenhill & Co. The transaction, unanimously approved by the Board of Directors of GHL Acquisition and Iridium as well as Iridium’s major shareholders, values Iridium at approximately $591 million enterprise value. Following completion of the transaction, the combined enterprise will be renamed “Iridium Communications Inc.” and will apply for listing on the NASDAQ. Existing owners of Iridium will maintain a significant stake in the combined company.