NEW YORK, March 3 (Reuters) - LPL Financial Holdings , the biggest U.S. independent brokerage firm, promoted Chief Financial Officer Dan Arnold to the role of president on Tuesday following the resignation of Robert Moore.

Moore, who was paid $3.12 million in cash, stock and options in 2013, the last year for which information was available, is leaving to become chief executive of Legal & General Investment Management America, a fixed-income money management firm in Chicago, LPL said. He joined LPL in 2008 as chief financial officer, when it was still a private company controlled by private equity firms, and was named president in January 2013.

Arnold has been with LPL since 2007 when UVEST, a brokerage firm he led, was purchased by LPL. Prior to replacing Moore as chief financial officer in 2013, he led strategy and then institution services at the company.

"We are always supportive of employees at any level of the company doing what is best for their careers and families," LPL Chairman and Chief Executive Mark Casady said in a prepared statement

The moves follow several other shifts of top executives at LPL in recent years. Bill Dwyer, president of national sales at the firm that works with 14,000 brokers, unexpectedly left in 2013 and is now an executive at rival broker RCS Capital Corp . Derek Bruton resigned as head of LPL's independent advisor services group in April 2014, when the company cited "concerns over his interactions with other employees."

LPL said that Tom Lux, who has worked in its finance department since 2009, will serve as acting chief financial officer while it conducts a search for a permanent replacement to Arnold.

The company also promoted Andy Kalbaugh and Bill Morrissey to the positions of divisional presidents for Institution Services and Independent Advisor Services, respectively, reporting to Arnold.

(Reporting By Jed Horowitz; Editing by Bernard Orr)