The buyer is investment management firm Wafra Investment Advisory Group Inc.
Balfour Beatty Infrastructure Partners LLP was set up in November 2010 as an independently managed infrastructure management business focusing on secondary opportunities in transport, energy and utilities. Its assets include Alkane Energy and Wightlink, the Isle of Wight ferry company.
Balfour Beatty has retained the right to further payment from the fund depending on its future performance.
"Our exit from Balfour Beatty Infrastructure Partners and sale of the fund interest further simplifies the group and maintains our existing balance sheet strength," said chief executive Leo Quinn.
"Exiting the infrastructure fund management market will allow our core infrastructure investments business to focus entirely on its highly successful primary investments portfolio which also offers further downstream opportunities for the Balfour Beatty Group," he added.