CIENA ANNOUNCES PRELIMINARY THIRD QUARTER 2004 RESULTS

8/3/2004, CIENA® Corporation  announced it expects to report fiscal third quarter revenue for the period ended July 31, 2004, of approximately $75 million, representing slight sequential revenue growth and year-over-year revenue growth of approximately 9 percent.

The Company stated previously it anticipated revenue growth of up to as much as 30 percent from fiscal second quarter revenue of $74.7 million. The Company attributed the difference between current expectations and its previous expectations to an ongoing environment of uncertainty resulting in cautious spending and deployment delays by its large service provider customers, including a deceleration of DSL-related orders in North America.

CIENA intends to report third quarter 2004 results on Thursday, August 19, 2004, prior to the open of the financial markets.