Ericsson has sold its enterprise PBX business to Aastra Technologies in order for it to concentrate on sales to service providers.

"We will continue to sell enterprise solutions, but they will from now on be sold exclusively by carriers and service providers," said Urban Gillström, head of Ericsson's enterprise business.

At the same time he wants to reassure existing customers that use either the old MD110 or the new IP PBX MX-ONE: "The roadmap for companies that want to move to IP in their own pace is still there. Nothing has changed," he said. He and his team will work closely with Aastra until the takeover, valued at 650 million Swedish kronor (£52 million), is completed in April, he said.

Aastra believes the acquisition of Ericsson's Enterprise Communication Business will provide the company with the increased scale to be a leading player in Western Europe, while creating an important footprint in a number of other markets, it said.

As a part of the deal Ericsson will also transfer 630 employees, of which some 360 are based in Sweden.

What this means for existing Ericsson customers depends on Aastra, said Steve Blood, vice president and voice agenda manager at Gartner Research.

"The issue here is the Aastra business model, which to date operates like a holding company of smaller PBX businesses. Aastra doesn't buy neat, innovating technology start-ups which are so essential to being a leader in this market," he said.

"If Astra management takes this opportunity to re-organise and focus on the enterprise, Ericsson gives it the scale and breadth to be a little more of a challenge in the European market. If it continues to operate the same business model of a holding company, this is no good news for Ericsson customers," Blood said.

Success will also be determined by how well Aastra articulates a unified communications proposition to the market, an area in which other players are much further ahead, said Blood. "Ericsson's customers should look closely at this product and market development plan," he said.

One Ericsson customer that isn't worried, at least not yet, is Electra Group of Sweden. It upgraded its PBX from an MD110 to an MX-ONE last November.

"It's a stable solution that meet our current demands. We have paid for our PBX, and now we want to enjoy that for a while. But if our users want features that the PBX doesn't have we will look elsewhere," said Electra CIO Ola Schwarz.