The only mobile phone maker in the top five not to have suffered a quarterly decline was Samsung, which bucked the trend with a respectable 9.1 percent increase in unit shipments to 34.8 million from 31.9 million during the last quarter of 2006.

"Samsungs success was mainly due to its strong sales growth in Asia," said Tina Teng, analyst, wireless communications, for iSuppli. "The South Korean company's mobile-phone shipments in Asia in the fourth quarter rose by an impressive 28 percent on a sequential basis, and by a whopping 57 percent compared to the first quarter of 2006. Samsung achieved a 13.8 percent mobile-phone market share in the first quarter of 2007, the highest level for the company since the second quarter of 2005."

However, this rise came as a double-edged sword for Samsung, with the company's increased percentage of low-cost mobile phone shipments cutting its Average Selling Price (ASP) by 10 percent compared with the previous quarter.

Motorola posted the most disappointing results among the top 5, with its shipments declining by 30.9 percent to 45.4 million units, down from 65.7 million in fourth quarter.

Nokia Corp. maintained its customary lead, shipping 91 million units during the first quarter, 13.3 percent higher than its two nearest competitors (Motorola and Samsung) combined. However, the company suffered a 13.6 percent decline in shipments compared to the fourth quarter, causing its market share to decrease to 36 percent, down from 36.4 percent in the fourth quarter.

Motorolas loss was also a boon to the other South Korean supplier, LG Electronics, which only saw shipments decline by 6.5 percent compared to the last quarter of 2006. iSuppli says LG's operating margin improved significantly during the quarter, rising to 6.6 percent, up from 1.3 percent during the fourth quarter of 2006.

"Motorola's stronghold has always been in the Americas regionbut this represents less than 30 percent of the global mobile-phone market," Teng said. "The company has suffered weak sales in Europe and has been late to market with UMTS, hurting its sales and profitability."

However, Teng noted that Motorola's market-share and volume declines may partly be intentional. While unit shipments were down, the company managed to increase its ASP to $119.20, up 0.41 percent from $118.72 in the fourth quarter of 2006.

iSuppli says Nokia performed well in the fist quarter in the important Chinese market, with shipments rising by 7.5 percent compared to the fourth quarter. It adds the Finnish firm holds the No. 1 position in shipments of mobile phones to high-growth emerging markets and also is the leader in UMTS technology. The company is also said to have achieved a 16.2 percent operating margin, once again the highest among the top five. Sony Ericsson ended the first quarter with 21.8 million unit shipments, down 16.2 percent from 26 million in the fourth quarter of 2006. The companys phone ASP declined by 6.1 percent sequentially.

"Sony Ericssons decline in ASPs can be explained by the company's expanding sales of the low-end J series handsets targeting emerging markets," according to Teng.