Yell Group Plc, the publisher of the U.K.'s Yellow Pages phone directories, fell the most in three weeks in London trading after U.S. Yellow Pages publisher R.H. Donnelley Corp. cut its 2008 forecast.
Yell shares dropped 30.5 pence, or 11 percent, to 242.5 pence. Shares of Reading, England-based Yell fell 30 percent last year.
``While R.H. Donnelley's downgrades could read as an indication Yell is gaining significant market share, we think it is more likely driven by the deteriorating U.S. advertising outlook,'' London-based UBS analyst Ian Whittaker wrote in a note.
R.H. Donnelley fell as much as $7.35, or 41 percent, to $10.45 in New York. The shares of the Cary, North Carolina-based company traded at $11.05 as of 12 p.m.
Yell spokesman Jon Salmon declined to comment.
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