BlackRock's Larry Fink thinks Carl Icahn's cash cow "can't last"

Larry Fink thinks Carl Icahn's cash cow can't last.

"The S&P 100 companies are paying out 108% of earnings through dividends and stock repurchases," Fink said. "That can't last."

Fink got a chance to speak without being interrupted by Carl Icahn, and on Tuesday morning at the DealBook conference in New York he railed against activist investors.

Icahn and Fink got in a bit of a tiff over activism at CNBC's Delivering Alpha conference this summer.

Fink, the CEO of $4.5 trillion asset manager BlackRock, railed against "quarterly capitalism" he says is embodied by the biggest activist investors.

Specifically, he is opposed to the biggest companies in the US to take on enormous bond deals and leverage to pay out investors clamoring for quarterly dividends.

That activist investors are currently allocated several times, at $127 billion, what they had even 5 years ago for deals, may be exacerbating this problem, he said.

But Fink says the blame extends into the boardroom.

He went on to blame "bad management" who are "focusing on short-term actions to defend their position in business."

"You should be listening to your shareholders with that long-term view," instead of activists, Fink said.

When pressed for people he has disagreed with lately, Fink demurred to discuss Icahn specifically.

But it's not hard to figure out who he may have been talking about.