March 18 (Bloomberg) -- Google Inc., owner of the world's most-used Internet search engine, lost its bid to get European Union-wide trademark protection for ``Gmail,'' the name of its Web-based e-mail service.

The Gmail name is too similar to an existing German trademark, according to a ruling by the EU's trademark agency published on its Web site this week. Google has been blocked from getting the EU rights to the name because of the trademark owned by German businessman Daniel Giersch for a slogan that includes the name ``G-mail.''

``There is a likelihood of confusion'' between the two trademarks, the Alicante, Spain-based trademark agency ruled in the Feb. 26 decision. The ``common element Gmail'' is so similar that people ``will be misled into thinking that the marks indicate a shared commercial origin.''

Giersch, who received his German trademark in 2000, has been entangled in a series of European court cases against Google since the Mountain View, California-based company started its e- mail service in 2004. Giersch, chief executive officer of P1 Private GmbH, uses the name for a mail business that lets users send electronic files and messages through a central e-mail system. The G stands for his last name, he says.

Google, which owns trademark rights to Gmail in more than 60 nations, is ``disappointed'' with the decision, spokeswoman Kay Oberbeck said in an e-mailed statement today, adding that the company is examining the ruling and won't yet comment on a possible appeal. Google can appeal the decision to the European Court of First Instance in Luxembourg, the EU's second-highest court.

`Legal Recourse'

``I would expect them to appeal until they have no more legal recourse,'' Greg Sterling, an analyst at Sterling Market Intelligence in San Francisco, said by telephone today. ``Ultimately, if they fail they will have no other way but to create a separate brand.''

Giersch's full slogan -- ``G-mail ... und die Post geht richtig ab,'' which translates as ``G-mail ... and the mail really takes off'' -- helps promote the 33-year-old German's electronic mail-delivery business.

The trademark agency rejected Google's argument that there was no risk of confusion with its Gmail name when looking at Giersch's slogan as a whole. The main element of his trademark is the word G-mail, according to the agency, the Office for Harmonization in the Internal Market. The second part of the slogan and the black and yellow colors, which are different from Google's, are of secondary importance, it said.

`Conceptual Similarity'

``The common element Gmail, with or without a hyphen, gives the signs an overall visual, phonetic and conceptual similarity, which is such that the relevant public'' when confronted with the names in the electronic mail industry ``will be misled,'' the agency ruled.

The ruling upholds a decision by the agency's lower board in January 2007 to reject Google's bid based on the ``strong likelihood of confusion'' with Giersch's German trademark.

``I find it striking that a U.S. company clearly keeps losing in Germany and Europe-wide and yet it won't acknowledge that it is wrong,'' Giersch said in a telephone interview today.

Google, which uses the name GoogleMail instead of Gmail in Germany, in July lost a German court bid to claim the right to Gmail from Giersch. Google also has used GoogleMail in the U.K. since 2005 when it settled a similar dispute with London-based Independent International Investment Research.

`GoogleMail'

``Use of the Gmail trademark will continue in countries other than the U.K. and Germany, where users of `GoogleMail' will continue to enjoy the same experience as users of Gmail worldwide,'' said Oberbeck, the Google spokeswoman.

Google shares rose $19.29, or 4.6 percent, to $439.16 by p.m. New York time on the Nasdaq Stock Market. The shares have dropped 36 percent this year.

The EU agency, which grants trademarks that are valid across the 27-nation bloc, has the power to reject applications based on similar trademarks that already are registered in any EU country.

To contact the reporter on this story: Stephanie Bodoni in Luxembourg at sbodoni@bloomberg.net

Last Updated: March 18, 2008 16:42 EDT