Lucas van Praag, a Goldman Sachs partner and the global head of corporate communications for the firm will leave at the end of March, according to a memo obtained by Reuters.

Van Praag, 62, joined the investment bank in 2000 as the director of corporate communications for Europe, and over the next 12 years oversaw corporate communications in Asia before being tapped to manage communications for the firm globally.

Lucas has played a critical role in helping the firm navigate through one of the most difficult and testing environments the firm has faced, particularly during the recent financial crisis and its aftermath, Chief Executive Lloyd Blankfein and Chief Operating Officer Gary Cohn wrote in the memo.

His strategic counsel and deep understanding of complex issues defined his career at the firm as did his warmth, natural inclusiveness and determination in the face of relentless demands.

Van Praag will continue to provide strategic advice as a consultant to the securities firm, according to the memo.

A spokesman for Goldman Sachs confirmed the contents of the memo but declined to comment further.

Speculation that van Praag was likely to leave the firm had grown in recent weeks, as media reported that Richard Siewert Jr., a former top adviser to Treasury Secretary Timothy Geithner and a White House press secretary under President Bill Clinton, was in talks to take on a similar role at the investment bank.

Van Praag, a colorful character who was often seen by bank chief Blankfein's side at public events, is the latest high-level departure from Goldman's public relations team, following Stephen Cohen, Andrea Rachman and Ed Canaday who all left over the past 12 months.

(Reporting By Katya Wachtel; Editing by Maureen Bavdek)