Among the stock activity stories for Tuesday, May 12, from AP Financial News:

NEW YORK (AP) _ Shares of Ciena Corp. declined after an analyst downgraded the telecommunications and network equipment company, saying its key customers are "aggressively cutting" their capital expenses.

TRENTON, N.J. (AP) _ Shares of drugmaker Pfizer Inc. jumped after an analyst issued a report citing benefits of its planned acquisition of rival Wyeth and stating that those were "not yet reflected in the stock."

HARTFORD, Conn. (AP) _ Shares of McDermott International Inc. ticked higher, a day after the engineering and construction firm reported a 37-percent drop in first-quarter profit, while still exceeding Wall Street expectations.


NEW YORK (AP) _ Despite Holly Corp.'s strong first-quarter results, a continued deterioration in demand and challenging industry fundamentals will pressure the petroleum refiner, an analyst said as she lowered her profit estimate for the company.

PORTLAND, Ore. (AP) _ Shares of Winn-Dixie Stores Inc. soared following a strong third-quarter report from the Jacksonville, Fla.-based grocery store operator.

NEW YORK (AP) _ Teen retailer Buckle Inc. continued to post strong same-store sales growth of 18.2 percent in April, but a slowdown in men's wear may spell trouble for sales and earnings growth, said an analyst, downgrading the company.

NEW YORK (AP) _ Shares of MBIA Inc. slipped as the company tempered some excitement from reporting a first-quarter profit by saying its underlying performance remained weak.

NEW YORK (AP) _ Las Vegas Sands Corp. may look to sell some Asian assets, which a JPMorgan analyst said Tuesday could bring in "a sizeable amount of net proceeds" for the casino operator.