Conor McGregor's bid to cash in on his brand across the EU has suffered a setback.
It follows the European Union Intellectual Property Office (EUIPO) in Spain rejecting his application to register his name as a trademark for the sale of clothing across the EU.
EUIPO has turned down the application by the MMA star's McGregor Sports and Entertainment Limited (MESL) after upholding an objection by Dutch clothing firm McGregor IP BV.
The Dutch company, which sells clothing and accessories under the McGregor brand, told EUIPO that consumers might believe goods sold by Conor McGregor's firm are part of the products marketed by it.
In the ruling, EUIPO rejected McGregor's trademark application for the sale of clothing, footwear and headgear.
It refused the trademark for clothing due to the likelihood of confusion among the public concerning the proposed Conor McGregor brand and the DD McGregor brand used by McGregor IP BV.
EUIPO also found that, contrary to the Conor McGregor company's opinion, the trademark signs of the applicant and the Dutch opponent "are visually and aurally similar to an average degree".
In adjudicating on the contest, the EU office found it appropriate to focus on the Netherlands, Finland and the Scandinavian countries, where it said consumers had a basic understanding of English.
It said the registered and proposed trademarks coincided in an unusual family name.
The office also ordered the McGregor company to pay the fees and costs incurred by the Dutch firm in the action.
The McGregor company now has the option of appealing.
In response, lawyers for Conor McGregor, European patent and trademark experts FR Kelly, denied that the two brands would be confused.
In a six-page rebuttal submission to EUIPO last autumn, the Dublin-based company said the trademark application by the fighter differed by the fact that it contained the forename Conor, which is not present in the trademarks of McGregor IP BV.
The MMA star's lawyers said there were "clear and obvious differences" between the trade mark of the Conor McGregor company and those of the Dutch McGregor.