Seattle--Boeing Co. and a group of key suppliers Lockheed Martin Corp., Raytheon Co. and British Aerospace plc are reportedly preparing to annouce an aerospace e-marketplace. Commerce One is said to be the technology partner. The companies are expected to make an announcement on Tuesday. ``I can tell you that Raytheon has been looking into business-to-business enterprises such as this,'' said David Polk of the company's media relations department, ``but we don't have any announcements at this time.'' ``It makes a lot of sense,'' said Steve Kafka, analyst at Forrester Research, Cambridge, Mass., of the planned e-marketplace. ``It creates instant volume, because these guys together control a huge fragment of the market.'' The aerospace industry is estimated to be a $500 billion market. It is unclear what form the e-marketplace will take. Industry observers say a simple auction site will offer marginal value, but an exchange focused on supply chain management could streamline the design and manufacturing process. The site planned by Boeing and its partners will likely face challenges from at least three other industry e-marketplaces in the works.