Symbian's licensees, which include most major mobile phone manufacturers, shipped 980,000 devices in the fourth quarter of 2002, and two million devices in that year in total.
The company has found increasing success as the high-end handsets based on its operating system find favour with users. However, Nokia's move to take a controlling stake in the company earlier this month has raised questions about Symbian's future, with some industry observers saying Nokia's competitors will be reluctant to incorporate the software into their most important products.
Other Symbian shareholders are preparing to block Nokia's move by exercising their own rights to buy Psion's shares, according to sources quoted by Reuters on Monday. This action could leave Nokia with as little as 46 percent of Symbian, the report said.
The Symbian OS, like Microsoft Windows CE, the Palm OS and embedded versions of Linux, brings handheld computer features to mobile phones. Most established mobile phone makers have licensed the Symbian OS, while PalmSource and Microsoft have teamed up with manufacturers from outside the mainstream of the mobile phone industry.
Symbian licensees shipped more than one million phones a month for the first time in December, while the end of 2003 was the fourth consecutive quarter in which more than one million Symbian-based handsets shipped, the company said. In December, licensees had shipped a total of more than 10 million units.
Motorola, Nokia, Siemens and Sony Ericsson shipped eight new Symbian models worldwide, including two models shipped to operator 3 for its European 3G network, while a total of 18 handsets were shipping from five licensees in the fourth quarter. Twenty-six more handsets were under development by nine licensees.
Symbian chief executive David Levin said the rising number of Symbian handsets on the market was a good sign for the company, downplaying fears that Nokia would turn Symbian into a glorified subsidiary. "Symbian's commitment to all its licensees and its unique independent governance structure make it the logical partner for the industry as software becomes a progressively more critical asset," he said in a statement.
Symbian was created in June 1998 as a partnership between Psion, Nokia and Ericsson, with Motorola becoming a shareholder a few months later. Symbian was meant to drive the smartphone market through the creation of operating systems based on Psion's EPOC software that could be used by any mobile-phone maker.
However, Motorola sold its stake to Nokia and Psion in 1999, in a move seen by analysts as evidence that other operating systems -- perhaps made by Microsoft or based on Linux -- could instead dominate the smartphone operating system market.
According to Dean Bubley, an analyst at Disruptive Analysis, the sale of Psion's stake to Nokia earlier this month is confirmation that Symbian is largely synonymous with Nokia, rather than being the cross-industry platform it was once meant to become.
"This announcement indicates that most other Symbian licensees are using the operating system just for niche products, rather than core and strategic parts of their product line," said Bubley when the buyout was announced.
Bubley added that this was this is particularly true of other licensees of Series 60, which is Nokia's implementation of Symbian for mobile phones that use only their numerical keypad, rather than a stylus, for input. Sony Ericsson relies on another implementation, called UIQ, which uses a stylus.
ZDNet UK's Graeme Wearden contributed to this report.