Nokia and Samsung Electronics increased their share of the mobile phone market in the second quarter, putting a squeeze on Motorola as market researcher Gartner reported an overall increase of cell phone deliveries.

"Motorola's woes continued and its global market share dropped to less than 15%," Gartner reported Thursday. Motorola has been under increasing pressure in recent months as sales of its mobile devices have plunged.

Motorola barely held onto its second place position in the rankings, and some analysts have placed Motorola and Samsung in a statistical tie. Motorola's share of market dropped to 14.9%, down from 21.9% in the same quarter a year ago.

The 270.9 million phones sold in the quarter represented an increase of more than 17% over the previous year's figures. "Emerging markets in Africa, Latin American and Asia/Pacific are still fueling growth," Gartner said.

Nokia's market share increased from last year's 33.7% to 36.9%, Gartner said. The company shipped nearly 100 million phones in the latest quarter. Gartner's mobile devices research director Carolina Milanesi said Nokia's market share is likely to continue to increase at the expense of Motorola.

Samsung's market share was 13.4% as the company continued to gain on Motorola. Also gaining market share was Sony Ericsson, which jumped to 9% from 6.6% in the previous year. LG Electronics' share increased slightly to 6.8% from 6.3% a year ago.

The market share figures are likely to increase the pressure on Motorola's chief executive Ed Zander, who is struggling to find a replacement for Motorola's successful Razr line of handsets. A brace of new handsets has been announced by Zander, but to date they haven't had a significant impact on the company's fortunes. Handset sales make up about one half of Motorola's business.