Mergers and acquisitions activity in the marketing sector rose 14% in the first quarter of 2015, with 280 deals worth a collective $8.4 billion taking place during the first three months of the year, according to corporate finance advisers Ciesco.

The figures indicate that the fast pace of deal-making last year – which was up 24% over 2013 -- is on track to continue this year.

WPP and Dentsu were the most-active marketing communications companies, with five deals each, but these established players were matched by newcomer Keda Group, a Chinese conglomerate that has historically focused on infrastructure, real estate and financial services. Keda also made five marketing services acquisitions, all within China.

The value of Keda's acquisitions totaled $474 million, putting it in third place behind WPP and Dentsu, but ahead of Publicis, Twitter, Omnicom, Havas, Facebook and Alibaba. Keda looks to have come from nowhere -- it did not feature in Ciesco's full-year 2014 report.

Of the 280 deals made in the first quarter, 131 were in the U.S., making it by far the most-active market. The U.K. was second with 36, followed by Canada, France and China with 12 each. Australia, Germany, India, Sweden and the Netherlands were also in the top 10 countries by deal volume.

Marketing technology was the most active sector, with 46 deals, followed by mobile (32), full service digital (25), and digital media (22).

Cross-border deals accounted for 30% of transactions, slightly behind last year's 33%, suggesting that the communications giants are beginning to shift focus towards consolidating operations in existing markets rather than prioritizing land grabs.

Afsor Miah, director of corporate finance at Ciesco, said, "Other deals to keep an eye out for this year include Dunnhumby, the data business that Tesco is looking to divest. [WPP CEO] Martin Sorrell has his eye on it, but will see strong competition from private-equity investors."

WPP declined to comment, but Mr. Sorrell has indicated interest in published interviews.

Tesco recently announced an annual loss of $9.6 billion, making a Dunnhumby sale – which could bring in as much as $3 billion -- look more likely as the U.K.'s biggest retailer seeks to cut costs and consolidate its core business.

Mr. Miah added, "There are also rumors of Google circling Twitter and InMobi, which should make for an exciting 2015." Google declined to comment, but sent along a link to a New York Times Bits Blog story headlined " InMobi Plans to Stay Independent, Dismissing Rumors of Talks With Google."

Contributing: Tim Peterson