Buffett told CNBC on Thursday it was Dimon who initiated the effort to talk about best practices for corporate governance. (Click here to read the open letter that the CEOs signed off on.)
"Jamie gave me [and others] a call ... probably a little more than a year ago," he continued, "and suggested we get together and see if we could come together on some general principles for corporate governance that might help show a pathway to the future."
The general rules by which companies are operated and controlled have evolved over the years, Buffett said, referring to the emergence of competing constituencies, especially with activist investors stepping up their efforts to influence the proceedings.
The process was designed around "creating a dialogue," Buffett said. "This is not something we're going to be passing around and hoping we get hundreds of signatures."
"We welcome other views on it," he continued. "These did not come down on a tablet from the mountain."
Addressing the cutthroat nature of being a publicly traded company, Buffett said he originally wanted Berkshire Hathaway to be private.
"I've had an interesting transformation on that. I originally would have preferred that Berkshire Hathaway be a private company. And over the years, my view on that has changed 180 degrees," he said. "I enjoy being a public company now.
"I like the fact that people put their trust in us, and we treat them like partners and they feel partners," he added.
Buffett said the "primary allegiance" of corporate boards should to the investors. "I believe that the board of directors is there to represent shareholders, the owners."
On the issue of dual-class stocks, the group generally disapproved, saying there should be "sunset provisions" in place.
Buffett acknowledged he has a dual class at Berkshire in the form of Class A shares and Class B shares.
"On balance, it's better to have one class of stock," said Buffett, but he added that the dual class works at Berkshire.
"As I give away my own shares, and I've given away about 40 percent [to charity] so far and I'll give away every share I have, I always convert the ... 'A' stock into the 'B' stock. So the 'A' stock will have less proportionately as it goes along," he said.
"We also have a provision that in the event of any kind of a corporate transaction, the 'A' stock cannot be treated differently than the 'B' stock. I think that's important and we put that in our paper," he added.