Mitel and Avaya shone in the telephony market last year, with both vendors' sales growing significantly compared with rivals.
In the fourth quarter, according to research firm Canalys, Avaya shipped more than 125,000 lines, compared with just over 76,800 for the same period in 2002.
Mitel's shipments almost tripled, from just under 20,500 in the last three months of 2002 to over 55,700 in Q4 2003.
"Mitel has been strong in retail, and Avaya has been aggressive as well," said Sandy Fitzpatrick, director and senior analyst at Canalys.
"Both companies, as well as Nortel, have done everything they can to hang onto their installed base."
Nortel took the number one position in the UK market, with 127,000 shipments, an increase of only 5,000 lines.
Overall, the UK telephony client premises equipment market grew by 10 per cent year on year, with a total of 558,000 lines shipped in Q4 2003, compared with 510,000 lines in Q4 2002.
Paul Templeton, Nortel's EMEA vice president of sales, said sales of low-end systems had remained consistent.
"The UK numbers in isolation do not present as clear a picture as the European Union [EU] figures," he said.
"Looking at the EU as a whole, it is apparent that smaller national manufacturers are beginning to struggle."
IP telephony now makes up five per cent of shipments, hybrid systems make up 76 per cent and traditional PBX makes up 19 per cent.
Roger Jones, EMEA business development director at Avaya, said: "Mitel is doing some quite innovative things with migration to IP. We have competed with it, and it's fair to say both Mitel and we have the IP story sorted out at the moment."
Jones said firms that upgraded early during the millennium bug panic were now coming back to the PBX market early, and predicted this would make a "natural lump" in the market over the next two years.
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