Worldwide mobile phone sales rose by 22% in the three months to September.
Handset sales hit 205 million, said research firm Gartner, which forecast total sales of 810 million for 2005.
Nokia continues to lead the market with a 32% share, but Motorola saw a big boost in sales as it sold 12 million of its Razr phones.
Sales grew more slowly than the 26% seen in the same period of 2004 - but surged over 40% in Eastern Europe, Africa and Latin America.
"Year on year sales grew in all regions as replacement sales in mature markets such as Western Europe and North America continued to drive growth while users in emerging markets joined mobile networks and acquired their first mobile device," said Gartner analyst Carolina Milanesi.
Market leaders Nokia and Motorola were seeing big sales of their more basic, low cost handsets in developing countries.
The developing world is a crucial market for vendors
"Although their market share is going up, this is putting pressure on their margins and profits," Ms Milanesi said.
"They need to find new applications and features that will continue to sell their more expensive phones in Western Europe and North America."
Gartner expects global mobile phone sales to rise a further 10-15% during 2006.