The deal, which is effective from January 1 2005, sees Envoy take control of the agency set up in 1990 by designers Tamara Williams and Tony Parker.
With more than 25 years' design experience in Europe, America and the Far East, Parker Williams has revenues of around £2.6m and includes Sainsbury's Chupa Chups, Danone and the Early Learning Centre among its clients.
According to Parker: "We are very excited about Envoy's investment in our firm. We realised the need to be a part of something that can take us to the next level without compromising our culture."
The acquisition is not Envoy's first foray into the UK. In 2001, it attempted to buy London advertising agency Leagas Delaney. However, the deal later collapsed and Leagas stayed independent.
Geoffrey Genovese, CEO of Envoy, said: "Parker Williams has a real energy and enthusiasm. Our team has seen the passion it has put into every brand it works on, and we are delighted that Parker Williams has decided to partner with us. Parker Williams will add tremendous value to the Envoy Group. Its strategic and creative expertise will be an asset to our team in both the North American and UK marketplace."
Envoy said it was currently in negotiations with four additional acquisition targets.
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