Britain's top bank association will soon review whether taxes, regulatory uncertainty and toughened compliance standards are prompting financial institutions to threaten to move their headquarters out of London. In a statement Tuesday, the British Bankers Association (BBA) said it had hired former U.K. regulator Hector Sants and other consultants with Oliver Wyman to send recommendations to the government later this year on how to better foster the financial industry. Sants served as the head of the now-defunct Financial Services Authority from 2007 to 2012, ahead of the creation of the Financial Conduct Authority. The effort follows speculation that some banks...