Previously support was provided by the Alliance, 4Children, the National Childminding Association and the National Day Nurseries Association, each working with their own membership bases.
Local staff from these organisations will be offered a transfer to the Alliance from 1 April.
The Alliance's development officers will give advice and training to pre-schools, nurseries, childminders, toddler groups and out-of-school clubs and link in with the work by local authority advisers in children's centres.
Jane Youdale, the Alliance's county manager for Essex, said the aim was to build a multi-disciplinary holistic team.
'Providers will continue to have a named contact who can offer support to their setting,' she said. 'However, it will mean that we can deliver more targeted, directed work using a referral process and concentrating in areas with the most identified needs. This links very well with Sarah Teather's vision of early intervention and a focus on the most disadvantaged children.'
Both the local authority and the Alliance are urging providers to continue membership with sector-specific organisations to ensure their concerns are heard at national level.
Ms Youdale said the reorganisation will help avoid duplication of visits. In the past a nursery with an out-of-school club would have been visited by different sector organisations.
Support will move from staff based in local areas to 'quadrants' to mirror plans to reorganise the running of the county's 86 children's centres. Contracts to run the centres are up for renewal in April 2011. Two-year contracts will start in April 2012.
Organisations are being invited to bid to form consortia to run all the centres in each quadrant.
Harriet Hill, head of Essex early years and childcare, said, 'This contract demonstrates Essex council's commitment to investment in the early years and childcare sector and recognition of the vital role it plays in supporting the best possible outcomes for children.'