Shares of

Ciena

(CIEN) - Get Report

were down for a second day, which some reports attributed to comments from a

BlueStone Capital

telecom analyst who raised concerns about a possible spending slowdown at one of the company's European customers.

Ciena, an optical networking company, recently fell $15.31, or 18.2%, to $68.69.

Additionally, French equipment maker

Alcatel

(ALA)

told analysts that it had become a supplier for long-distance company

Sprint

(FON)

, one of Ciena's largest customers.

The BlueStone analyst, Susan Kalla, said one of Ciena's customers,

Global TeleSystems

(GTS) - Get Report

, a London-based carrier, has been having debt troubles that might curtail that company's spending.

Kalla said the decision to lower Ciena's price target was "an overall demand call" that reflected a deteriorating financial condition at some carriers, as revenue growth is subsiding and cash flow is being squeezed. Also, the analyst indicated that the overall health of telecommunication companies, especially long-distance carriers, is "in rapid decline."

Kalla left open the possibility that Ciena could make up for any shortfall from the Global TeleSystems contract with deals from other carriers.