HAWTHORNE, Calif., March 15 -- OSI Systems Inc. has signed a definitive agreement to sell its wholly owned subsidiary, Silicon Microstructures (SMI), to ELMOS Semiconductor AG for about $6.5 million.
   The price includes $6 million in cash to be paid to OSI upon closing, and an additional $462,000 for certain capital equipment items being purchased by SMI from OSI Systems' UDT Sensors subsidiary. The sale agreement also includes a three year commitment from UDT Sensors to supply four-inch silicon foundry wafers to SMI, and to dedicate limited manufacturing facilities to be used by SMI for its etching operations.