Carat pitched against OMD UK, Starcom Group and the incumbent, Mediaedge:cia; ZenithOptimedia had earlier pulled out of the review. The other pitching agencies were told on Wednesday that they had not been successful, although a Saga spokeswoman refused to comment on Carat's appointment.
Saga, which has created a profitable niche selling investments, holidays and insurance to the over-50s, spends the majority of its budget below the line. Nielsen Media Research records its above-the-line spend as £8 million.
In October last year, Saga underwent a £1.35 billion management buyout backed by the private equity company Charterhouse Capital Partners. The deal netted Roger De Haan, the company's owner and the son of its founder, a personal windfall of £1.1 billion.
After De Haan's decision to stand down, Andrew Goodsell became Saga's chief executive. Despite going down the MBO route, there is still speculation that Saga will end up listed on the Stock Exchange.