Shares in Ascential, the owner of Cannes Lions, jumped more than 3.5% as investors welcomed the deal.
Michael Kassan, the chairman and chief executive of MediaLink, a US media advisory business which includes handling advertising account reviews and headhunting for clients, told Campaign he wanted to roll out the new offices "as soon as possible".
He said the ability "expand our footprint globally" and "tap into the deep resources" of Ascential" was a key reason to sell his business, which he founded in 2003.
"We’re ready to go," he said of plans to open a base in London, where Ascential, the owner of Cannes Lions, is headquartered. MediaLink’s UK home will be "initially" at least in an Ascential office.
Kassan, who is known for his high-level media contacts, said: "We’re in the midst of identifying talent coming over [from the US] to London." It is expected he will also recruit local UK talent.
He said the Hong Kong office could open within the next eight weeks, around the time that he plans to speak at a Campaign conference in Hong Kong in May.
He did not say how many people he planned to employ in London or Hong Kong but MediaLink has about 120 staff in four cities in New York, Los Angeles, San Francisco and Chicago.
Kassan first got to know Duncan Painter, the chief executive of Ascential, at Cannes Lions about two years ago.
He recalled "their first date" was when they were introduced at a party thrown by Joanna Coles, the Hearst magazines supremo and former Cosmpolitan editor, and Evan Spiegel, the founder of Snapchat, at the Hotel du Cap on the opening Sunday of the advertising festival.
Kassan, whose firm has been a highly visible presence at Cannes for years, recalled how Painter was introduced as "the guy who owned Cannes Lions".
At that point, two of Kassan’s friends who were standing in the same group quipped to the MediaLink boss: "Jeez, I thought you owned the Cannes Lions."
"No, apparently, I merely rent Cannes Lions from this guy," Kassan responded at the time.
Painter described MediaLink as the "number one brand" in its field and said its high-level contacts and business knowledge would help Ascential improve the quality of information that its other businesses sell to clients.
"It’s a perfect fit," Painter said, explaining MediaLink will be part of Ascential’s information services division, rather than the events arm of which Cannes Lions is a part of.
MediaLink has worked with Cannes Lions’ clients since 2011 and they will continue to work together but as separate businesses.
LionTree Advisors advised MediaLink on the sale to Ascential, which will pay $69m initially in cash. Further payments could make the acquisition worth $207m if MediaLink hits "stretching" targets by 2021.
It is not known if other potential buyers were approached.
Ascential floated on the London stock market at 200p a share in February 2016 and has risen 50% in value. The information and events group is now worth about £1.2bn.