Dell Inc., the world's second-biggest personal-computer maker, replaced Michael Cannon as president of global operations and Mark Jarvis as chief marketing officer as it strives to revive sales amid a worldwide recession.

Cannon will be succeeded by Jeff Clarke, and Jarvis will by Erin Nelson as part of a global reorganization, Dell said Wednesday. Cannon and Jarvis will leave by month's end. Clarke and Nelson already work for Dell.

Founder and CEO Michael Dell is trying to win back the PC sales lead held by Hewlett-Packard Co. He has ditched the company's direct-sales-only model to jump-start revenue growth and cut more than 11,000 jobs to reduce costs.

"This restructuring is in response to mediocre results," said Roger Kay, president of researcher Endpoint Technologies Associates Inc. in Wayland, Mass. "It is not enough. They do need to work on their product portfolio and their supply chain and distribution."

The company last quarter posted sales that trailed analysts' estimates by more than $1 billion.

Revenue from the Americas, which makes up almost half the total, fell 7.7 percent after customers pared budgets to shield themselves from the recession.

Dell shares rose 1 cent to close at $10.24. The stock has lost 58 percent this year.

Dell said it will reorganize its business units around three customer groups: large enterprises, public sector, and smaller companies.

Dell has eliminated about 13 percent of its workforce from a peak last year, aiming to save $3 billion a year by 2011, while expanding sales to almost 20,000 retail outlets, including Wal-Mart and Best Buy.