Range Online Media, which has gross assets of $12m, is based in Fort Worth, Texas, and specialises in paid search marketing and search engine optimisation.
Founded in 2001, it initially specialised in services to the retail and travel sectors, but more recently it has expanded into the technology, luxury brands, financial services, utilities and entertainment industries.
The agency's clients include Toshiba, Burberry, Aveda, Accor Hotels, Neiman Marcus and Macys.com.
Following the acquisition, Range will re-brand under the iProspect name and form the fourth US office in the iProspect global search network.
Range increases iProspect's reach to 21 offices in 17 markets worldwide, and is the sixth acquisition by Aegis's digital network, Isobar, in search marketing during this year alone.
The acquisition adds to iProspect's client roster in the retail sector, a key market for search marketing services.
Alongside its core SEM expertise, Range has developed proprietary technology to tackle the rapidly growing online media, social and emerging media spaces. These capabilities include unique site optimisation, online public relations optimisation, reputation management, advanced linking strategy and development as well as blog, podcast and video optimisation.
Robert Lerwill, chief executive officer of Aegis, said: "Demand for specialist search expertise is growing at around 25% a year. As a result, no business can ignore the importance of search to a marketing campaign: optimising both paid and organic techniques is key.
"Range Online Media gives us a significant boost in the retail sector in the US and a fourth office in the region. It also brings enviable tools and technology designed to measure the growing social media space, which we can leverage across the entire iProspect global network."
In July, Aegis has acquired French search marketing agency Aposition and earlier in the year it bought Thailand's leading search marketing specialist Globlet and rmsarcar.com in Germany.
This article was first published on brandrepublic.com