Shares of Lifeway Foods ( LWAY) were among the Nasdaq's winners Friday, rising 15% after the company said it would begin distributing its kefir milk drinks to a limited test market of up to 17 Chicago-area Wal-Mart ( WMT) stores.

"While we do not expect nationwide distribution at Wal-Mart stores in the near future, we are thrilled that we can continue to expand and penetrate the Chicagoland with our award-winning kefir in new mainstream outlets," the company said. "We hope this limited store distribution is successful to a point where we can then move to supply a larger number of Wal-Mart stores nationwide."

In May, shares of Lifeway soared after the company began selling its kefir products at Target ( TGT) stores. Shares were recently trading up $2.11 to $16.20.

Petco ( PETC) fell 13% after the pet goods retailer posted mixed second-quarter results and warned that third-quarter earnings would disappoint investors. The company posted earnings of $18 million, or 31 cents a share, on sales of $482.7 million. Analysts polled by Thomson First Call were expecting earnings of 31 cents a share on higher sales of $486.7 million. A year ago the company earned $19.3 million, or 33 cents a share, on sales of $438.5 million. Petco said that weak customer traffic during the most recent period hurt results.

Looking ahead, Petco forecast third-quarter earnings of 25 cents to 28 cents a share on a same-store sales gain of flat to up 2%. Analysts had been expecting earnings of 39 cents a share. The company said third-quarter results would be hurt by its decision to further improve customer service, more clearly communicate its marketing messages and complete its remerchandising initiative. "We believe the initiatives we have under way will enable Petco to extend its leadership position in an industry with healthy long-term prospects," the company said. "However, given current conditions in the overall economy and their effect on the retail sector, we are cautious about our expectations for top-line growth in the short term." Shares were trading down $3.42 to $22.13.

Shares of Fossil ( FOSL) rose 8% after the watchmaker said that it has advanced negotiations for a 10-year licensing deal with Guess? ( GES). Under the deal, which includes a renewal option, Fossil would manufacture and distribute Guess and Guess Collection watches beginning in January 2007. The companies plan to base minimum royalties on wholesale revenue of $1.36 billion for the 10-year term. Worldwide wholesale revenue is currently about $150 million for Guess and Guess Collection watches. Finally, Fossil said it plans to create a separate company for the Guess business. Shares of Fossil were trading up $1.56 to $21.74.

Zygo ( ZIGO) rose 13% after optical instruments supplier posted a fourth-quarter profit that topped expectations. The company reported earnings from continuing operations of $3.9 million, or 22 cents a share, on sales of $44.9 million. Analysts were expecting earnings of 17 cents a share on sales of $36.4 million. A year ago the company earned $3 million, or 17 cents a share, on sales of $36.3 million. Shares were trading up $1.44 to $12.34.

Shares of Atari ( ATAR) rose modestly after the video-game software publisher said it would sell its Humongous Entertainment studio to Infogrames Entertainment for about $10.3 million. The Humongous assets consist of intellectual property, existing inventory and license rights, Atari said. About $2 million of the purchase price represents pre-payment of future costs that Atari will incur as part of platform royalty advances, manufacturing costs and milestone payments. Looking ahead, Atari has been granted exclusive distribution rights through at least March 2006 for Humongous products in the U.S., Canada and Mexico. Shares were trading up 3 cents to $1.39.

NYSE volume leaders included Lucent Technologies ( LU), down 2 cents to $3.06; EMC ( EMC), up 15 cents to $13.07; Elan ( ELN), down 36 cents to $8.39; Pfizer ( PFE), up 4 cents to $24.91; and Hewlett-Packard ( HPQ), up 2 cents to $26.92.

Nasdaq volume leaders included Cisco Systems ( CSCO), down 9 cents to $17.39; Intel ( INTC), up 1 cent to $25.47; Sun Microsystems ( SUNW), up 2 cents to $3.65; OmniVision ( OVTI), up $1.67 to $15.05; and Microsoft ( MSFT), down 9 cents to $26.94.