LONDON (Reuters) - Britain is preparing to transfer over 400 million pounds ($527 million) to Iran as it seeks the release of a jailed Iranian-British aid worker, The Telegraph newspaper reported, citing unidentified British sources. Nazanin Zaghari-Ratcliffe, a project manager with the Thomson Reuters Foundation, was sentenced to five years after being convicted by an Iranian court of plotting to overthrow the clerical establishment. She denies the charges. Britain has sought legal advice over whether it could transfer the funds which it owes as a result of a disputed arms deal in the 1970s. Diplomats told the newspaper that any payment should not be linked to the fate of Zaghari-Ratcliffe. The Thomson Reuters Foundation is a charity organization that is independent of Thomson Reuters. It operates independently of Reuters News.  A spokesman for Britain s Foreign Office could not be reached for comment out of normal business hours. 