INTELSAT, a satellite operator being purchased by four buyout firms, plans to sell $2.55 billion of junk bonds next month to finance the transaction, said a person familiar with the offering who declined to be identified. The company hasn't determined a maturity for the securities being sold, the person said. Deutsche Bank, Credit Suisse and Lehman Brothers are managing the sale, another person said. An investor group that includes Apax Partners Worldwide LLP, Permira Advisers Ltd., Apollo Management LP and Madison Dearborn Partners Inc. agreed to buy Bermuda-based Intelsat on Aug. 16 for $3 billion.