Value investing giant Chris Browne stepped down from his day-to-day activities as managing director of Tweedy, Browne yesterday after 40 years at the firm. Browne has been battling undisclosed health issues for the past two years.

Browne served as one of five managing directors of the firm, a member of the firm’s management and investment committees and chairman of the Tweedy, Browne Funds, a mutual fund group comprised of Tweedy, Brown Global Value Fund; Tweedy, Browne Value Fund; and Tweedy, Browne Worldwide High Dividend Yield Value Fund.

He came to the firm named in part for his father, Howard Browne, after graduating from The University of Pennsylvania in 1969, when it was still a relatively small RIA. He became a partner in 1974. As of June 30, 2009, Tweedy, Browne had approximately $8.5 billion invested globally for individuals, institutions and family groups worldwide.

“This has been a difficult decision for me, but in the past two years I have had to deal with personal health issues, and there are other things I want to accomplish with the rest of my life,” Browne said in a statement released Thursday morning. “While my health issues are now mostly resolved, I took this as a wake up call about the fragility of life. I am confident that the investment professionals we have assembled will do a great job going forward—so confident that I am leaving virtually all of my personal investments with the firm.”

Browne and his brother William, also a managing director, were the second generation of his family to earn tenure at Tweedy, Browne. Their father served as partner of the firm from 1943-1980.

Brown gave back to his Ivy League alma mater, establishing the Browne Center for International Politics and the Browne Distinguished Professorships in Schools of Arts and Sciences at the university. He is a frequent speaker on behavioral finance and his book, The Little Book of Value Investing, is widely read and appreciated in the financial services industry.

Browne will serve as a senior advisor at Tweedy, Browne. He will also retain his equity interest in the firm.