The move comes as the Dutch construction giant confirmed it expects to make a half-year loss of £32m.
The Ballast Phoenix recycling operations are based in Lincolnshire where the firm processes incinerator bottom ash into construction aggregates.
Ballast Phoenix will be sold to H2 Equity Partners by the end of this month.
Ballast Nedam said the deal will have “no impact on job numbers” and will yield a book profit of £17.5m.
The firm blamed its half-year losses on cost overruns in the first half of 2014 on the A15 road job in Holland.
It added: “An agreement in principle has been closed with the banks on financing Ballast Nedam until 2017.”