SAN JOSE, Calif., Mar. 13 -- SDL Inc. has acquired Brucknell, UK-based Queensgate Instrument Ltd. The terms of the purchase agreement call for payments of up to $210 million consisting of initial payments of $3 million in cash and $57 million in SDL stock -- valued at the average closing price for the 20 trading days ending February 28, 2000 -- as well as contingent payments of up to $150 million based on Queensgate's pre-tax profits in 2000 and 2001.Privately held Queensgate is a manufacturer of optical network monitoring modules for long-haul terrestrial fiber optic transmission systems. Queensgate reported revenues of approximately $9 million in calendar year 1999; the company has approximately 110 employees. The parties announced that Queensgate would continue to operate as a wholly owned subsidiary of SDL Inc. Ken Reay, Queensgate's CEO and co-founder, will continue as managing director of the new SDL subsidiary, and will report to Greg Dougherty, chief operating officer of SDL.