The transaction includes the 10MW St Breock wind farm in the Cornwall area and 8MW Ramsey II project in Cambridgeshire.
Under the agreement, BlackRock will assume project debts of £21m and REG will receive upfront cash consideration of £13.1m, with a further £1.9m payable after commissioning in 2015.
REG will oversee construction of the projects under a construction management agreement and will operate the wind farms on behalf of BlackRock via an asset management agreement.
REG will reinvest the proceeds into its portfolio of approved projects including the 4MW Rodbaston, 4MW French Farm, 6MW Brackagh Quarry and 0.9MW Barlborough developments.
Some of the money will also be invested in REG Bio-Power projects, planned to be built in 2015.
REG chief executive officer Andrew Whalley said: "We are delighted to continue our strong partnership with BlackRock through the sale of these two projects as we demonstrate the value REG is creating through its development strategy.
"REG will maintain close links with the local communities in which these projects are based as part of its oversight of the important community funds, which will support local initiatives throughout the wind farms’ operating lives."
REG has also signed a £4.8m term loan facilities agreement with Caterpillar Financial Services to finance the 18MW bio-power plant at Whitemoor Business Park, near Selby in Yorkshire.
The Whitemoor project, which is in the last stages of testing, is anticipated to start operations by the end of October 2014.
