UPDATE 6-Iran amasses more enriched uranium than allowed by nuclear deal

DUBAI/VIENNA, July 1 (Reuters) - Iran announced on Monday it had amassed more low-enriched uranium than permitted under its 2015 deal with major powers, its first major step in violation of the deal since the United States pulled out of it more than a year ago.The U.N. nuclear watchdog, the International Atomic Energy Agency (IAEA), which monitors Iran's nuclear programme under the deal, confirmed in Vienna that Tehran had breached the limit.The step could have far reaching consequences for dipl