The two most senior commodities executives at Morgan Stanley are leaving the bank after compliance breaches linked to the use of communications tools, according to two people familiar with the matter.

Nancy King, global head of commodities, and Jay Rubenstein, head of commodities trading, are leaving, the people said, asking not to be named discussing internal matters. Morgan Stanley declined to comment.

The bank (MS) is one of the biggest commodities dealers on Wall Street alongside Goldman Sachs Group Inc., JPMorgan Chase & Co. and Citigroup Inc.

The veteran executives’ departures come after the bank discovered the use of unauthorized electronic means of communication. It didn’t find any wrongdoing, but the use of those communication channels went against policy, the people said.

King and Rubenstein didn’t immediately respond to messages seeking comment.

King joined Morgan Stanley 34 years ago, trading oil and rising through the commodities division to become the most senior woman in the business on Wall Street. Rubenstein, who many considered her likely successor, joined in 2007 to trade power and later became head of power and gas, according to their LinkedIn profiles.

SparkSpread first reported the departures.