The agency has been looking for a New York base for a while as increasingly its international clients – which now makes up between 10 to 20 per cent of its portfolio – are headquartered in the US.
"The kind of services that we provide, increasingly we like to be closer to a number of head offices and New York scores big in that," Lansons co-founder and CEO Tony Langham told PRWeek.
Lansons has worked with Intermarket for several years and has acquired a 51 per cent stake in the business, with plans to buy out the remaining equity over the next few years.
Intermarket is a strategic communications consultancy based in New York and founded by Matt Zachowski and Martin Mosbacher in 1986.
The business has 17 staff and says it is rated among the top 10 specialist financial PR firms in the US. It will rebrand to ‘Intermarket Lansons’ in the summer.
The combined annual fee income of the two businesses is about £13m ($17m).
Langham said the immediate focus is to grow Intermarket’s offering to provide a "wider range of reputation management, employee engagement crisis offerings in New York".
He said a medium to long-term objective for Lansons is to expand into Germany, and then Brussels.
"As a business we are ambitious for ourselves and our clients, and the next phase of our development is international expansion in key markets that build upon our existing international consultancy capabilities," Langham said.
"Many of our international clients have a footprint in both London and New York and major businesses are seeking more internationally-based consultancy. This presence in the world’s biggest communications market provides considerable opportunity and potential for long-term growth at a time when companies are striving to define their purpose globally."
Mosbacher added: "We have long seen New York and London as two synergistic parts that collectively make up an important communications hub. This is why we have always worked with strong partners in London – none stronger than Lansons."