After-Hours Buzz: YUM Falls as China Same-Store Sales Down 13% in March Amid Bird Flu Scare ... BBBY, MSFT & More

Check out which companies are making headlines after the bell Wednesday:

Yum Brands - The restaurant chain said its same-store sales tumbled nearly 13 percent for its China division. This included an estimated decline of 16 percent at KFC. Shares dropped in extended-hours trading.

"Within the past week, publicity associated with Avian flu in China has had a significant, negative impact on KFC sales," said the company in an SEC filing. "Historically in these situations, we have educated consumers that properly cooked chicken is perfectly safe to eat, and we will continue to do so. We do not anticipate providing any further updates regarding China Division same-store sales until our scheduled first-quarter earnings release on April 23, 2013."

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Bed Bath & Beyond - The retailer posted earnings of $1.68 a share, in line with expectations, while revenue edged past expectations at $3.40 billion versus projections for $3.39 billion. Meanwhile, the company handed in current-quarter earnings estimates that missed Wall Street forecasts but said it expects mid-single digit to low double-digit earnings growth for the full year. Shares climbed in extended-hours trading.

Shares of PC vendors including Microsoft, Hewlett-Packard, Dell and Intel declined after worldwide shipments of personal computers tumbled 13.9 percent in the first quarter, according to market researcher IDC, the biggest drop since the firm began issuing quarterly numbers in 1994.

International Paper - Daniel Loeb's Third Point said it has added to it position in the company during the first quarter.

Integra LifeSciences - The surgical products manufacturer said it is voluntarily recalling certain products and handed in earnings guidance that disappointed Wall Street estimates for its first and second quarters. Shares plunged in extended-hours trading after being briefly halted.

Ruby Tuesday - The restaurant chain posted earnings of 10 cents a share, excluding one-time items, matching Wall Street expectations. Meanwhile, revenue was $307 million compared to projections for $312 million. Shares edged lower in extended-hours trading.

Fortinet - The network security appliances company said it expects to post first quarter earnings of 10 cents a share on revenue of between $134 million and $136 million, disappointing analysts who expected the firm to report a profit of 12 cents a share on sales of $140 million. Shares plunged in extended-hours trading. Fellow networking security vendor Check Point Software Technologies also declined.

Zumiez - The apparel store posted March comparable-store sales that gained 2.1 percent, exceeding expectations for a decline of 8.2 percent, according to a StreetAccount estimate. Shares rallied in extended-hours trading.

Apogee - The glass products maker posted earnings of 15 cents a share, missing expectations for 17 cents a share, while revenue was in line with estimates at $180 million. In addition, the company handed in full-year guidance that was at the lower end of forecasts. Shares slid in extended-hours trading.

Xerox - Piper Jaffray initiated coverage of the photocopy machine and printer maker with an "overweight" rating and a price target of $12. Shares edged higher in extended-hours trading.

—By CNBC's JeeYeon Park (Follow JeeYeon on Twitter: @JeeYeonParkCNBC)

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