The agencies replace Grayling and Proteus, while 3 Monkeys, Camargue, Ptarmigan and Trimedia remain on the roster. The PR review will be effective from 1 April.
The agencies will share high-profile behaviour change campaigns such as the £18m 'Recycle Now' campaign and the recently launched 'Love Food Hate Waste'.
They will work with WRAP's in-house PR team, led by head of press and PR Amanda Barry-Hirst, who took over responsibility for the press office last year.
WRAP has made 31 members of its staff redundant ahead of expected cuts to its budget in April.