Consumer goods giant Unilever is proposing to close a number of sites with the loss of up to 800 jobs, while investing £40 million in its biggest UK factory, the firm announced.
The plans involve the closure of factories in Swansea and Slough and a distribution site in Bridgend, while an office Ewloe, North Wales would also close and work be transferred.
The proposals include investment of £40 million in Unilever's "historic home" of Port Sunlight, Wirral on Merseyside, with the creation of 150 new jobs. Work would transfer from Ewloe to Port Sunlight, where the workforce would increase from the current 1,500 to 2,000.
The proposed changes, to take effect by the end of 2013, could lead to 500 direct job losses and around 300 contractor and third party jobs. Some jobs will also be outsourced to Unilever's IT centre in Bangalore, India.
Amanda Sourry, chairman of Unilever UK and Ireland, said: "Like many companies today, Unilever faces the challenge of creating growth opportunities against a backdrop of very tough economic conditions in Europe.
"While Unilever is growing well in the UK and globally, it will always be necessary to make changes which raise our game and ensure our continued success. We believe these proposals would substantially strengthen our platform for long-term growth and competitiveness.
"The proposals announced today will be reviewed thoroughly and the outcome shared with our employees as early as possible. However, we understand that this period of uncertainty will cause concern for some of our employees who would be affected if changes were to be made, so we are fully committed to conducting all review and consultation processes properly and responsibly in order to provide clarity and certainty as soon as possible."
Reviews of the proposals are expected to be concluded in the autumn, with a final decision taken in September.
Wales' business minister Edwina Hart said: "Today's announcement will be a devastating blow for Unilever's workforce and their families in Wales. Officials from Welsh Government recently met with senior executives from Unilever to discuss the impact of the company's plans in Wales.
"We asked the company to fully consider the range of support offered to businesses by the Welsh Government and invited them to work together with us to implement a more sustainable solution for Wales by seeking to maintain current operations at its Welsh sites. The proposals for Ewloe, Swansea and Bridgend are therefore very disappointing, however we are hopeful Unilever can offer future opportunities for some of its north Wales workers through investment at its site at Port Sunlight, Merseyside."