Jan. 11 (Bloomberg) -- Yell Group Plc, the publisher of the U.K.'s Yellow Pages phone books, had its biggest gain in London trading in a month on speculation about a bid from Google Inc.

Yell rose as much as 4.4 percent, the biggest increase since Dec. 10. The stock climbed 5.50 pence, or 1.7 percent, to 331.25 pence at 8:37 a.m. in London, valuing the company at 2.6 billion pounds ($5.1 billion).

``The rumor that Google may bid for Yell has been around before, and I'm not surprised to hear it has surfaced again,'' said Jimmy Yates, a London-based trader at CMC Markets. ``Yell has lost almost half its value in the last 11 months and certainly looks more attractive now as a takeover candidate.''

The Independent newspaper in the U.K. reported today that a ``market source heard talk of a 500 pence-per-share bid'' for Yell by Google. Spokespeople for Yell and Google couldn't be reached immediately to comment.

Yellow Book, the largest independent yellow pages publisher in the U.S., accounts for about half of Yell's sales. Yell, which was spun off from former phone monopoly BT Group Plc in 2001, competes with phone companies such as AT&T Inc. and search engines including Google.

To contact the reporter on this story: Simon Thiel in London at sthiel1@bloomberg.net.

Last Updated: January 11, 2008 03:39 EST