The announcement follows a four-way competitive pitch.
Freuds handles consumer PR for a number of Mars brands, but told PRWeek it has never worked on Dolmio.
Freuds did not respond to a request by PRWeek for information about which agency previously held the UK consumer brief for the sauce brand.
Porter Novelli has previously worked for Mars on its Uncle Ben’s and Wrigleys brands in the US. The agency declined to comment.