Raytheon Co. plans to withdraw from the medical equipment business, selling off two subsidiaries and eliminating $2 million in annual losses, officials said. The sale price of the units to three buyers was not revealed. Varian Associates of Palo Alto has agreed to buy Machlett, a Stamford, Conn.-based X-ray tube manufacturing plant. A spokesman said many of Machlett’s 420 employees could lose their jobs when operations are transferred to California. Raytheon Medical Systems, an X-ray equipment and diagnostic machinery maker headquartered in Madison, Ill., will be sold to Fischer Imaging Corp. of Denver and Summit Service Technologies of Hudson, Ohio.