WPP plans to spend 300 million pounds over the next three years to return the world's biggest advertising group to growth by reducing the number of agencies it runs and hiring more talent in New York.

The British owner of the JWT and Ogilvy agencies has lost 40 percent of its value in the last year and been forced to cut its sales and profit forecasts after it lost some major clients and others cut their spending.

On Tuesday it said it would maintain and prioritise its dividend over buybacks and deals. It added that full-year organic net sales were likely to be down by 0.5 percent this year, an improvement on the 1 percent drop it predicted in October.