Instead, companies should clean up their operations to be more friendly to the environemnt, they said.
Policymakers and campaigners have been pushing the financial industry to do more to hold companies to account over their climate plans, and the CEOs of BlackRock and Deutsche Bank have been championing sustainable investments - a stance BlackRock enforced last week by backing green activism at Exxon Mobil and Chevron.
Larry Fink, chief of asset manager BlackRock, challenged the view that it is good when companies sell their dirtiest assets, particularly given those assets might then be less available to public scrutiny.
Divestment doesn't change the world, Fink noted. "It just goes from a transparent organization to an opaque organization that is not going to get us to where we want to go as a society," he said on an online conference organized by Deutsche Bank. "I don't believe in divestiture of public companies."
Christian Sewing, CEO of the German lender, said the bank was getting numerous mandates to advise companies to get rid of the "bad part" of their production, which then doesn't get reported under private ownership.
"That doesn't help the next generation. That is not the right thing to do," Sewing said.
(Reporting by Tom Sims and Patricia Uhlig; Editing by David Holmes)