Sept. 22 (Bloomberg) -- Hewlett-Packard Co., the world's largest personal-computer maker, may buy back as much as $8 billion in shares, matching its largest repurchase.

About $3 billion remained under the previous repurchase plan, approved last year, Hewlett-Packard said today in a statement. A buyback for the full amount would equal about 166 million shares, or 6.8 percent of the stock outstanding, based on the closing price Sept. 19.

Chief Executive Officer Mark Hurd is rewarding investors after hanging on to the lead in PC shipments for two years in a row, taking customers from Dell Inc. Last month, Hewlett-Packard reported third-quarter profit that surpassed analysts' estimates after introducing sleeker laptop designs.

``It's positive, but mostly expected,'' said Jayson Noland, an analyst at Robert W. Baird & Co. in San Francisco. ``H-P's been in a buyback mode for a while. We don't know if this changes the trajectory at all.'' He advises buying the shares.

Hewlett-Packard fell $1.10 to $47.16 at 4 p.m. in New York Stock Exchange composite trading. The stock has declined 6.6 percent this year, compared with a 32 percent drop for Dell.

The company, which had $14.8 billion in cash and short-term investments as of the end of July, bought back as much as $1.6 billion worth of its shares in the third quarter. Last year, Palo Alto, California-based Hewlett-Packard increased its authorization to $8 billion from $6 billion.

Microsoft Corp., the world's largest software maker, said today it will repurchase as much as $40 billion in stock. The company also plans to raise its dividend and issue its first commercial paper. Sneaker-maker Nike Inc. also announced a buyback worth as much as $5 billion.

Market Lead

Hewlett-Packard had 18.1 percent of PC shipments in the latest calendar quarter, compared with 15.6 percent for Round Rock, Texas-based Dell, according to Gartner Inc. Dell's share rose almost 1 percentage point from a year ago as CEO Michael Dell attracted more shoppers through stores, aping Hewlett- Packard's retail strategy.

Hewlett-Packard is fueling sales growth by expanding in other areas, such as computer services. Last week, the company announced plans to cut almost 25,000 jobs in the next three years, part of its integration of Electronic Data Systems Corp., the world's second-biggest computer-services provider.

To contact the reporter on this story: Crayton Harrison in Dallas at tharrison5@bloomberg.net

Last Updated: September 22, 2008 16:04 EDT