The, which was launched last year, will be joined by three more high-tech models, dubbed the Razr black, the SLVR and the PEBL.
Bigger rival Nokia has this year started moving a large part of its portfolio to clamshells after it lost market share in 2004 due to its focus on monoblock models.
The SLVR will come out in the third quarter, which is when Motorola will also introduce a round mobile phone dubbed the PEBL. Under Jim Wicks, elevated to chief designer last year, Motorola will develop two families of phones, one square and one round.
"We finally discovered the right direction," Amer Husaini, vice president for Motorola's mobile devices group in Europe, Middle East, Africa and South Asia, said at 3GSM in Cannes, the world's biggest mobile trade show.
Under new Chief Executive Ed Zander, Motorola turned around its handset operations last year. It gained global market share to 15.3 percent from 14.5 percent, and more than tripled operating profits after introducing popular new models of which it could make sufficient quantities--breaking with a tradition of problems with logistics and manufacturing.
While the new four-letter models will be for the standard second-generation networks, Motorola also unveiled three new handsets and one data card for faster third-generation mobile networks aimed at multimedia consumers and computer users.
Many operators opened third-generation (3G) networks to consumers last year, with 61 UMTS networks open by late 2004, connecting 16 million subscribers. Vodafone started selling 3G services to consumers in November in 13 countries.
Motorola will introduce the E1120 monoblock model with a built-in camera of 3 megapixels for high-detail pictures, and the E1060 model, which is aimed at music aficionados and which will feature the iTunes Music Player. Motorola said last year that software would become the default music player on Motorola handsets.
"We're committed to have iTunes as the default music client, but we'll also continue to support other music players such as RealPlayer, Husaini said.
Apple's iTunes Music Player has become popular on the back of the company's iPod music jukebox, which is the world's leading portable music player. Motorola phone users will be able to carry a limited number of songs in the iTunes format. Also at the Cannes show,upcoming phones that would store and play music.
The A1010, available in the first half, will succeed the current A1000 3G phone, adding more features.
All phones will run on Motorola's own operating system, except the A1010, which will run on Symbian. More Linux phones are in the pipeline for this year, but it is not clear whether they will be sold outside Asia, Husaini said.
The computer data card will be able to handle the higher speeds that come with HSDPA networks, the improved version of UMTS that will be used by some operators toward the end of 2005. That is also when Motorola's card will be ready.
At the trade show, Motorola's network division is showing how HSDPA can boost the speed of a 3G network so that 10 songs can be downloaded onto a phone in less than a minute.