WASHINGTON, April 14 (Reuters) - The U.S. Senate voted 53-45 on Wednesday to confirm former derivative markets regulator Gary Gensler as head of the country’s top securities markets regulator, spelling a tougher regulatory regime for Wall Street. Gensler is expected to be sworn in as U.S. Securities and Exchange Commission (SEC) chairman in coming days. A former Goldman Sachs banker and a professor at MIT Sloan School of Management, Gensler most recently led President Joe Biden’s transition plan for financial industry oversight and previously served under former Democratic President Barack Obama as chair of the Commodity Futures Trading Commission (CFTC).