Advanced Micro Devices gained market share at Intel's expense in the first quarter, as AMD saw strong sales across its microprocessor portfolio, a market research firm said Tuesday.

AMD's share in terms of revenue rose 2.3 percentage points to 12.8%, while Intel saw a drop of 2.5 points to 79.1%, iSuppli said. The decline ended a string of four quarters of sequential growth for Intel in 2008.

"AMD increased its allocation of global microprocessor revenue due to strong performances in each area of its microprocessor portfolio, particularly in its notebook products," iSuppli analyst Matthew Wilkins said in a statement. "This was an impressive feat given the economic downturn and the weakness in the PC and server markets."

Overall, global microprocessor revenue in the quarter fell 20.6% to $6.9 billion from $8.6 billion during the same period a year ago, iSuppli said. In calculating market share, iSuppli uses revenue from all types of general-purpose microprocessors, not just x86 chips used in PCs. Intel and AMD make x86 CPUs.

After a slight decline in market share in the fourth quarter of 2007, Intel gained share steadily in 2008 from 79% in the first quarter to 81.6% in the fourth quarter.

Intel widened its lead over AMD partly because of its Atom processor, which had major success in netbooks. Shipments of the inexpensive mini-laptops are the only PC category to show double-digit growth during the economic recession. All other categories have seen declines.

However, Intel also did well last year because of the strength of its broad product line for desktops, servers, and laptops, iSuppli said. AMD also sells products in those markets.

Although AMD managed to increase share in the first quarter, the chipmaker, along with Intel, saw overall revenue decline as a result of the global economic downturn, iSuppli said. The poor economy is expected to hamper the microprocessor business for the rest of 2009. Full-year global revenue is expected to reach $28.6 billion this year, down 15.8% from $34 billion in 2008.

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