Third sector organisations will be responsible for about a quarter of the £400m worth of contracts won by support services company Serco under the Department for Work and Pensions' Flexible New Deal scheme.
Contracts drawn up under the scheme, which helps the long-term unemployed to get back into work and begins this week, will be outcome-based, so their exact value cannot be calculated.
But a Serco spokeswoman said that voluntary groups would be running about 25 per cent of its business under the scheme.
She said about 40 per cent of Serco's subcontractors in Wales were third sector organisations, including conservation charity BTCV and mentoring charity Sova.
A spokesman for Working Links, a public-private-voluntary sector partnership that has a £560m, five-year contract under the Flexible New Deal, said it was setting up 85 agreements under which voluntary groups would be involved in providing services across the four areas in which it is running the scheme.
He said that Citizens Advice, CSV Wales and the Salvation Army were among the charities that would be involved.
Business training firm A4e will also be working with third sector partners, and back-to-work charity Tomorrow's People and the Turkish Cypriot Community Association were among those it will have as subcontractors.