The market for IP telephony in the UK has yet to mature and sales are still volatile, according to the latest figures from Canalys.

The figures, for the third quarter 2003, show that four rival vendors swapped positions in terms of line shipments. Avaya took the top spot from Nortel, while Mitel trumped Cisco on shipments.

However, the results show that the market is in its early stages, and there are still peaks and troughs, according to Sandy Fitzpatrick, director at Canalys. Smaller vendors are also losing out, she added.

"The market for telecoms is growing; it's going up 4.3 per cent year on year. Avaya and Nortel, in particular, are winning at the expense of smaller players such as Siemens and Alcatel," she said.

"Shipments can be dependent on the types of deal that vendors are making, and because the technology is relatively new to the market, it's a case of a small number of large installations."

Clive Sawkins, Avaya's vice president of UK and Eire, unsurprisingly welcomed the results. "We're happy that the strategy is working.

"I am quite worried, however, that the 'others' shipments is just as big as any other single company. The numbers seem volatile quarter on quarter, but this is a marathon, not a sprint," he said.

Paul Templeton, vice president of enterprise at Nortel in EMEA, said: "If you look at EMEA as a region, we are up 20-odd per cent year on year."

Tim Stone, Cisco's voice marketing manager in EMEA, said Cisco does not reveal sales figures below a regional level. "We sold 116,000 IP phones in EMEA in that quarter," he said. "There was a 44 per cent increase in sales from Q2 in the region."

Cisco's introduction of Call Manager Express, aimed at sub-100 line installations, is likely to make an impact on numbers in the new year, said Fitzpatrick.