Moody's downgraded its debt ratings and assigned a stable rating outlook. WPP's share price rose 5.9% amid wider market gains in morning trading to 399p, a gain of 22.5p.
In a statement, Moody's said: "The rating action reflects Moody's opinion that given the backdrop of still weak business fundamentals and limited visibility for media services companies combined with WPP's stated policy of using free cash flows to enhance shareholder value, the company is unlikely to improve relatively high measures of relative indebtedness in the near term."
It goes on to say that its outlook is based on the expectation that any further deterioration of WPP's profit levels, if any, would be moderate.
WPP Group, headed by chief executive Sir Martin Sorrell, has been announced as the big winner in the Burger King advertising review, with Young & Rubicam agencies picking up the bulk of the $340m (£216.4m) account.
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