NEW YORK (CNN/Money) - Shares of Wal-Mart moved higher on Wednesday after the retail heavyweight said same-store sales rose a better-than-expected 6.2 percent in May.

Embattled conglomerate Tyco International recouped some losses sustained after its chief executive suddenly resigned earlier this week. Tyco was the most active stock on the Big Board.

But shares of Williams Cos. fell as much as 17 percent after federal regulators threatened to revoke the power trading licenses of the company.

Wal-Mart Stores (WMT: up $0.96 to $54.96, Research, Estimates). The world's largest retailer said it expects sales at its Wal-Mart discount stores open at least a year to rise 5 percent-to-7 percent in June.

Tyco International (TYC: up $0.53 to $17.30, Research, Estimates). Shares of the embattled conglomerate rose a day after ex-chief Dennis Kozlowski, who resigned abruptly Monday, was charged with cutting illegal deals to avoid more than $1 million in taxes on valuable old paintings.

Redback Networks (RBAK: up $0.05 to $2.03, Research, Estimates). The company stock rose after analysts raised earnings estimates for the network equipment maker on expected partnerships, improving sales, and lower operating expenses.

Tower Automotive (TWR: up $1.10 to $11.95, Research, Estimates). The auto parts-maker raised its second-quarter earnings forecast because of stronger-than-expected sales and lower interest expense, prompting shares to rally.

Veridian (VNX: up $2.15 to $18.15, Research, Estimates). Shares rose as high as $18.25 after the company, which specializes in national security programs specifically for the intelligence community, priced its initial offering at $16 late Tuesday.

Cooper (COO: up $3.81 to $50.76, Research, Estimates). The eye care products maker reported a 14 percent increase in second-quarter profit and raised third-quarter estimates as it begins to benefit from acquiring the contact lens business of Britain's Biocompatibles International.

Candie's (CAND: up $0.14 to $4.47, Research, Estimates). The apparel maker said first-quarter net income nearly tripled, as results were boosted by lower expenses and an income tax benefit. The company said net income for the first quarter ended April 30 was $1.1 million, or 5 cents per share, up from $393,000, or 2 cents per share, a year before. Candie's said it believes long-term targets for sales and earnings growth of about 20 percent are achievable.

WebMD (HLTH: up $0.50 to $6.51, Research, Estimates). The Internet health-care and information provider said it repurchased 14.1 million shares of its common stock from Cerner in a private transaction at a purchase price of $6.01 per share.

Millennium Pharmaceuticals (MLNM: up $0.64 to $13.62, Research, Estimates). The company said U.S. regulators granted fast-track status for its experimental drugs to treat multiple myeloma and leukemia. The designation from the Food and Drug Administration means Millennium's products, MLN341 and MLN518, will be reviewed in an expeditious manner.

Microsoft (MSFT: up $1.68 to $51.66, Research, Estimates). Credit Suisse First Boston raised its June quarter estimate on the software maker by 3 cents to 45 cents a share and maintained a "strong buy" rating on the stock. The firm said that despite the $100 price cut for the Xbox video game unit, it thinks profitability concerns are overdone and believes that the company is likely to show better-than-expected profitability in its desktop and software business.

Phelps Dodge (PD: up $1.20 to $40.20, Research, Estimates). Merrill Lynch upgraded the copper producer to "neutral" from "sell."

BEA Systems (BEAS: up $0.74 to $10.90, Research, Estimates). Bear Stearns upgraded the storage equipment maker to "attractive" from "neutral."

Perot Systems (PER: down $3.43 to $14.55, Research, Estimates). The company run by former U.S. presidential candidate Ross Perot peddled a detailed blueprint of how to exploit market loopholes to raise power prices when it set up the computer systems behind California's electricity markets, the Los Angeles Times reported, citing a California state senator.

Pathmark Stores (PTMK: down $4.26 to $17.24, Research, Estimates). The grocery store chain, which runs 138 supermarkets in the New York, New Jersey and Philadelphia metropolitan areas, said net income for its first quarter ended May 4 fell to $2.8 million, or 9 cents per diluted share, from $5 million, or 16 cents per share, a year earlier. Analysts surveyed by First Call expected profit of 15 cents a share. Sales slipped, and Pathmark said the "disappointing" trend has continued into the current quarter.

Williams Cos. (WMB: down $2.09 to $9.12, Research, Estimates). The Federal Energy Regulatory Commission threatened to revoke the power trading licenses of four energy companies, including Williams, for failing to properly respond to its probe of trading practices in the western United States.

Manugistics (MANU: down $2.04 to $5.90, Research, Estimates). Goldman Sachs downgraded the software provider to "market perform" from "market outperform" a day after the company warned of a first-quarter loss and job cuts.

eFunds (EFDS: down $3.93 to $9.32, Research, Estimates). The provider of electronic debit payment services lowered its second-quarter and 2002 estimates Tuesday. WR Hambrecht Wednesday cut its 2003 revenue and earnings-per-share estimates for the company.  

-- from staff and wire reports