Ubben, managing partner at ValueAct Capital Master Fund, has resigned from Acxiom's board of directors after two years, stating that the company is presently "on the right path". He did not give further reason for his resignation.
Before joining the board, Ubben led two takeover attempts for Acxiom by ValueAct Capital in 2005. Ubben was later elected to the board of directors in 2006.
Last year, Acxiom accepted a $3bn (then worth £1.46bn), $27.10 per share buyout plan from ValueAct Capital and Silver Lake, which would have taken Acxiom private. But the deal was ultimately terminated at the last minute when Silver Lake expressed unwillingness to proceed.
Ubben, in a statement, said: "I have been pleased to have served on the board for the past two years and to help move Acxiom forward. I continue to believe that Acxiom is a global leader in its markets.
"Its leadership is on the right path, and I have every expectation that the company will long continue to bring value to its customers and shareholders."
John Meyer, Acxiom CEO and president, said: "Jeff Ubben has been a positive influence on Acxiom and has made significant contributions to our board of directors since joining in August 2006.
"We have benefited from his insights, and while he will no longer be on our board, I intend to continue to seek his advice."
Acxiom shares closed on Friday down 4.7%, dropping $0.39 to $7.86 (£4.89) per share.