The first job losses to be announced by new Cadbury owner Kraft Foods will see its factory near Bristol closed by 2011.

The US-based firm, which agreed a deal to take over the Bournville giant last week, said following extensive talks with senior management at Cadbury, it has reluctantly accepted plans to close the Somerdale manufacturing facility.

That means up to 400 jobs are set to be axed, amid plans to switch production to Poland.

Kraft said that the previous Cadbury regime’s plans to close the site were too far down the line to be overturned.

The company said: “It has now become clear that the investment required to reverse the closure programme would be so significant that alternative plans were not viable. Cadbury has already invested more than £100 million in building new production facilities in Poland and the majority of the lines have, or are about to be, transferred by mid of this year.”

Kraft Foods chief executive Irene Rosenfeld added: “In our recent talks with Cadbury senior management, it became clear that it is unrealistic to reverse the closure programme, despite our original intent to do so. While this is a difficult decision, we have moved quickly to end any further uncertainty.”

She continued: “We remain committed to investing in growing our combined business in the UK and will continue to support Cadbury’s existing £30 million investment plans for the Bournville site. During the next six months we are conducting a strategic review of our combined manufacturing network. We continue to believe that the combination of Kraft Foods and Cadbury will accelerate growth to the long term benefit of our employees.”

The company has said that it will honour Cadbury’s previous undertakings to Somerdale employees concerning the terms and conditions of the closure and the commitment to rebuild the Fry Club on the Somerdale site.

Ahead of the announcement, union leaders had said this looked like “the first promise to be broken by Kraft”.