APCO Worldwide

Global head Margery Kraus

Ownership Independent

Fastest growing offices New York, Dubai, Singapore

Key clients eBay, Mars, Microsoft

In January, it acquired a majority stake in StrawberryFrog, an advertising and marketing agency.

Notable business wins include Cruise Lines International Association, Masdar and media relations for the UN Conference on Trade and Development. The agency also extended its remit with GE to handle the firm's Olympic sponsorship support for London 2012.

New additions to the agency include James Acheson-Gray, who joined as MD of the London office, from Grayling, and Mike Tuffin, formerly executive vice-president at America's Health Insurance Plans, who became MD in Washington DC.

Although the UK lobbying team took a knock at the end of 2011 when Darren Murphy and Razi Rahman left to set up their own agency, the gap was plugged by heavyweights Lionel Zetter as senior counsellor alongside Michael Burrell, the former vice-chairman of public affairs at Edelman.