Investment bank Lazard terminated a managing director for inappropriate behavior over the weekend, according to a source familiar with the situation.

Incoming CEO Peter Orszag sent a memo to staff this weekend informing them that the company had dismissed a managing director in the bank's financial advisory unit, the source said. Lazard took action after investigating the behavior, which occurred at a personal event at which employees were present, the source said, without naming the banker.

Orszag currently leads Lazard's financial advisory unit overseeing deals.

Bloomberg News reported earlier on the firing, saying many investment banks are taking a harder line on the behavior of their executives in light of investor and regulatory criticism of the culture on Wall Street.