Regulators yesterday moved to restore the reputation of London as a financial centre after scandals involving two poorly governed emerging market mining companies tarnished the City and threatened to drive business to other capitals.

New listing rules, designed to stop majority shareholders from destroying a company’s credibility and value, were hailed by some of the City’s biggest investors as a significant step for London’s standing as a place to float. But lawyers in New York warned that the changes might hinder new offerings on the London Stock Exchange depending on how the rules were implemented.

The rules will require majority shareholders of premium listed corporations, including the biggest groups on the FTSE 100, to keep an “arm’s length” from the company and not interfere with day-to-day control.