Ackman, head of Pershing Square Capital, called Icahn’s office to say he decided to “forgive Carl,” and Icahn returned the favor and said, “I forgive you,” according to the account.
The two told the Journal they spoke for about a half hour on Thursday.
If the peace lasts, it will end one of the greatest feuds in Street history.
During CNBC’s “Fast Money Halftime” show last year, Icahn and Ackman called in and squared off over a number of issues, with Ackman’s aggressive bet against Herbalife at the center. Icahn bet the other way, and the two warred bitterly over the issue and a general clash of personalities.
Some highlights of the televised battle:
Icahn in Ackman: “He’s the quintessential example that on Wall Street, if you want a friend, get a dog.”
Ackman on Icahn: “What I can tell you is, this is not an honest guy, and this is not a guy who keeps his word. This is a guy who takes advantage of little people.”
Those belligerent sentiments seem to have changed, though, with Ackman even raising the possibility that two of the financial world’s most aggressive activist investors actually could team up.
Read More Big money activism: Helpful or harmful?
“There is a much greater possibility that we are on the same side than the opposite,” Ackman said.
The Journal account ironically attributes recent comments that Icahn made to CNBC as helping set the reconciliation wheels in motion.
Read More Carl Icahn defends Ackman, slams Lipton
“We have our differences, but I never said he’s not a smart guy,” Icahn said.
Read the full Journal story here.