The Alzheimer's Society will create more than 100 new jobs as part of a restructure in a bid to win more service delivery contracts from local authorities and primary care trusts.
The charity will set up 49 regional administrative centres in England, Wales and Northern Ireland, which will manage its branches in each region. They will also be the main points of contact for PCTs and local authorities.
It means there are 311 jobs under review at the charity, but 435 new positions will be created.
Andrew Ketteringham, director of external affairs at the charity, said he hoped the vast majority of the 311 people whose jobs were under review would be able to move into one of the new roles.
"The way we run our services is changing," he said. "In the past, we have manufactured a service and sold it, but now we are being commissioned by the public sector, so we have to be able to respond to its demands.
"The restructure will make us better at meeting the needs of the public sector and better at winning contracts to provide services for it."
Ketteringham said it was not yet clear how much the charity would spend on the restructure, but that it was likely to lose money in the next two years and recoup it once the new system was in place.
Thirty-five per cent of the charity's income comes from statutory funding. Ketteringham said this figure was likely to increase, but that voluntary income would always be "crucial" to the charity.
The restructuring process is expected to begin in April next year.