Apple has filed a trademark application for an \"iWatch\" in Japan, fuelling speculation the US tech giant is preparing to introduce a wearable computing device to go up against products on stream from Google and Samsung. The firm has long been rumoured to be working on introducing an \"iWatch\", which would represent the biggest gadget launch by the firm since the iPad mini last year. The trademark application was filed on June 3, according to the Patent Office. \"The application is under examination process for approval, which in general takes some four to five months,\" a Patent Office official said. No one from Apple in Tokyo was immediately available to comment on the application. Wearable computing, including Google\'s Glass eyewear, is considered as the next frontier in consumer electronics following smartphones. Competition in the \"smartwatch\" market is already heating up, with Google, Microsoft and Samsung Electronics rushing to develop their own watch-type computing devices. Sony last week unveiled the latest version of its SmartWatch, which links with smartphones to receive alerts about phone calls, emails and updates from social networks, as well as including a music function. ABI Research estimates that 1.2 million smartwatches will be sold globally this year. -- Dow Jones Newswires contributed to this story -- si/hg/dan