U.S. President Donald Trump's plan to cut the corporate tax rate to 15 percent would be a tailwind for profitability at Warren Buffett's Berkshire Hathaway Inc., but won't fundamentally change how its business units operate, Buffett said.

“The deferred taxes that are applicable to unrealized gains on securities would all be applicable to us," Buffett said during Berkshire's annual shareholders meeting on Saturday. "We have $90 or $95 billion in gains, and our owners, dollar for dollar, will participate in that ... If the rate were to drop 10 percent, that $9.5 billion is real."

Buffett, a Democrat who vocally supported Hillary Clinton's unsuccessful White House candidacy, added that the impact of lower corporate taxes would not translate into higher profits across all of Berkshire's many dozens of businesses.

Regulated utility units, for example, are not likely to enjoy lower tax rates as savings, in Buffett’s view, would be passed onto customers. He also said that a lot of the benefits of lower corporate taxes would likely be competed away.

Buffett, 86, said: “We’ve had a lot of (tax cuts) in our lifetimes … it’s certain that some of a lower corporate rate would be competed away, and it's sure that some of it would inure to the benefit of shareholders."

In February, Barclays analyst Jay Gelb said cutting the corporate tax rate even to 20 percent could boost Berkshire's book value by $27 billion because of a decline in its deferred tax liability. A cut to 15 percent could boost book value by $36 billion, he said.

"I can't recall sending anything out to our managers saying, 'Let's do this because the tax law is going to change,'" Buffett said.

Berkshire Vice Chairman Charlie Munger, who was also answering shareholder questions during the annual meeting, agreed with the assessment.

"We're not going to change anything at the railroad just for some little tax jiggle," Munger said, referring to Berkshire's BNSF unit.