Last year an advert appeared in the European Journal which called for firms interested in running some Essex County Council functions to contact the authority.
Now, leaders of the union Unison, which represents up to 20,000 workers at the county council, were told that eleven consortia, including some of the world's major companies, have now expressed an interest.
Out of those eleven consortia, five have now been asked to present money saving ideas to the council.
Mick Marney, Unison organiser at County Hall, said a recent two day briefing on the Essex Transformation Programme "raised more questions than it answered".
Mr Marney added he was now "even more concerned" about job losses at the council than when the outsourcing plan was first mooted.
But Mr Marney said: "We have not been given explanations, reasons or the potential number of job losses, or if our people may be transferred to the private sector.
"It makes me even more concerned than when the advert appeared."
Lord Hanningfield, leader of Essex County Council, stressed the aim is to divert £200 million of money spent in the back office into front line services.
A spokesman for Lord Hanningfield said: "As the current economic climate worsens it is our responsibility to make sure we have explore all options for keeping Council Tax as low as we can, and this process is about seeing how we can be more efficient and effective in delivering our services."
The moves by Lord Hanningfield's Conservative administration have been backed by county Liberal Democrat Group leader Cllr Tom Smith Hughes.
Five groups have been asked to present money-saving ideas by next month and by April a preferred bidder for the outsourcing project may be named by Lord Hanningfield's Cabinet.
Groups applying are:
●Capita with Axon Global Telereal and PriceWaterhouseCoopers
●IBM with Trillium and WS Atkins
●Mouchel with VT, Cap Gemini, Experian, Ipsos Mori and Outcomes UK
●Tata Consultancy
●T-Systems with Vertex, PA Consulting, and Drivers Jonas.