NEW YORK - Twitter has failed in a bid to trademark the word 'tweet' after the US Patent and Trademark Office ruled that three other companies developing applications for the site already had a prior claim on the word.
Tweet, the name for the short messages its users write, has become synonymous with the micro-blogging site. A variety of applications such as Tweetdeck, Tweetboard and Tweetie are already in use on the site.
But despite this the US Patent Office rejected Twitter's bid on the grounds that three other companies - Tweetmarks, Cotweet and Tweetphoto - had applied for trademarks and that there was likely to be confusion between them.
The US Patent Office said in a notice dated July 1 that all three companies had posted their applications using the expression 'tweet' before Twitter.
All three companies' operations appear to be based around the use of Twitter. Tweetmarks is a bookmarking tool, Cotweet is aimed at the corporate market and Tweetphoto is a photo sharing application.
Coincidentally, on July 1 Twitter co-founder Biz Stone revealed in a blog that the company had applied the patent to the word tweet but that he was happy for developers to use it. He did not know the US Patent Office had rejected the Twitter application.
Stone said: "We have applied to trademark Tweet because it is clearly attached to Twitter from a brand perspective, but we have no intention of 'going after' the wonderful applications and services that use the word in their name when associated with Twitter.
"In fact, we encourage the use of the word Tweet. However, if we come across a confusing or damaging project, the recourse to act responsibly to protect both users and our brand is important."