The report from Strategy Analytics also said that mobile phone shipments in the U.S. grew more than 6 percent year to year in the third quarter of 2008 despite a deepening economic downturn.

Samsung overtook both Motorola and LG, vaulting from third to first with 22.4 percent market share in the quarter. It was the first time Samsung ever reached the top spot in the U.S.

“Samsung’s growing retail presence and an attractive handset portfolio for each of the big four operators proved crucial in grabbing the prestigious title of the No. 1 vendor in the world’s single largest handset market,” said Bonny Joy, an analyst with Strategy Analytics.

Beleaguered Motorola took the unfamiliar No. 2 slot posting 21.1 percent share.

Mobile phone shipments in the U.S. reached 47.4 million units during the quarter, up 6.2 percent from 44.6 million units in the third quarter of 2007.

The research firm credits aggressive pre-stocking by distributors before the holiday season as a key reason for the heavy shipment volumes in the third quarter. Attractive phones, carrier packages, and strong subsidies also played key roles.

But third-quarter pre-stocking could negatively affect fourth-quarter shipment numbers as a combination of the credit crunch and uncertain prospects for the holiday season come into play.

“Carriers were stocking handsets this quarter at more than usual levels, perhaps affected by the credit crisis,” Mr. Joy said. “As a result we may see shrinkage in volumes in the fourth quarter.”

Canadian handset maker RIM, which in the second quarter attained double digits in market share for the first time, stayed steady at 10.2 percent share. The BlackBerry-maker took the No. 4 slot.

AT&T's iPhone subsidies gained Apple the No. 6 slot with 5.7 percent share, while south Korean phone maker LG slipped from No. 2  to No. 3.