By Jonathan Stempel
NEW YORK (Reuters) - A judge on Thursday rejected Citigroup Inc's <C.N> bid for a preliminary injunction to stop AT&T Inc <T.N> from using the phrase "AT&T thanks" on a customer loyalty program, which the bank called too similar to its trademarked "thankyou."
U.S. District Judge Katherine Forrest in Manhattan said Citigroup has not shown that customers would likely be confused, or that it would suffer irreparable harm, if AT&T kept saying "AT&T thanks" while the bank's lawsuit continued.
She also said AT&T provided solid evidence that forcing it to start saying something other than "AT&T thanks" would cause an "expensive and significant disruption."
Citigroup had no immediate comment. AT&T said in a statement it was pleased with the decision, and maintained that "the law does not allow one company to own the word 'thanks.'"
The fourth-largest U.S. bank by assets sued AT&T on June 9, one week after the Dallas-based phone company launched "AT&T thanks" in a dispute that threatened to damage a co-branding relationship dating to 1998.
Citigroup said AT&T went too far, having known it would object after the New York-based bank had since 2004 extensively used "thankyou" on its own customer loyalty and reward programs.
According to court papers, Citigroup's "thankyou" programs have about 15 million members in the United States, and 1.7 million customers there have AT&T co-branded credit cards.
But in her 30-page decision, Forrest said the companies are targeting different markets, finance and telecommunications, and use different logos, typefaces and colors in their marketing.
She said this counteracts the slogans' "obvious similarities, at least when considered in the abstract: 'AT&T THANKS' and 'THANK YOU' share five central letters, are partially pronounced similarly, and both convey a message of gratitude."
Forrest also found no evidence of consumer confusion, and said Citigroup's evidence of what it called "many negative comments" about the "AT&T thanks" program show that consumers in fact could distinguish it from the bank's program.
The judge has not ruled on whether AT&T actually infringed Citigroup's trademark.
The case is Citigroup Inc v. AT&T Inc et al, U.S. District Court, Southern District of New York, No. 16-04333.
(Reporting by Jonathan Stempel in New York; Editing by Jonathan Oatis and Grant McCool)