WPP today reported first quarter revenue rose 7 percent to £2.2B ($3.7B), continuing a recovery started in 2010.

PR and public affairs at units like Burson-Marsteller, Hill & Knowlton, Cohn & Wolfe, Ogilvy PR Worldwide and Public Strategies rose 5.5 percent on a like-for-like basis to £207.9M ($333.3M) during the quarter.

WPP singled out PR business in Asia-Pacific, Western Europe and Mideast as performing well, with Ogilvy and C&W, along with its Buchanan U.K. unit and Hering Schupener in Germany, also getting a nod.

CEO Martin Sorrell said profits and margin are ahead of budget and “well ahead” of last year. He plans to lay out £200M in acquisitions this year.

“The pattern of revenue growth in 2011 has started similarly to the second half of 2010, with improvements across all sectors and geographies,” he said.

WPP is based in Ireland but is planning to move back to the U.K. as corporate tax rates are slated to be cut, Sorrell said.

Advertising (+9.3%) and WPP’s branding and identity, healthcare and specialist communications category (+6.9%) were the top gaining categories in Q1.

U.S. growth at 7% to £807.9M continued a strong performance akin to an “emerging market,” said Sorrell. The U.S. outpaced Western Europe (+1.9%) and the U.K. (+5.4%), but was behind emerging markets like Asia-Pacific, Latin America, Africa, Mideast and Central/Eastern Europe (+11.5%). Argentina and India surpassed 20% growth for the quarter, followed by Brazil, China, Korea and Russia, which ranged from 15-20%.

Looking ahead, Sorrell cited forecasts of stronger growth in Asia Pacific and Latin America “counter-balanced by lower growth in the U.S.”

Sorrell said new business in Q1 was “reasonably strong” at $1.3B, not as good as Q1 of 2010 but in line with the quarterly average for last year.