EATONTOWN, N.J., Aug. 3 -- OpNext Inc.has closed a $321 million investment from Clarity Group, an equal partnership between Clarity Partners, a Los Angeles-based private equity investment firm, and Marubeni Group, a major Japan-based trading house. OpNext was formed from the fiber optic components business unit of Hitachi Ltd.'s Telecommunications & Information Infrastructure Systems Group. OpNext will be launching a line of 40 Gb/s transceiver modules in 2002 designed to offer highspeed optical transmission.