The Washington Post, the newspaper whose reporting helped topple a president and inspired a generation of journalists, is being sold for $250 million to the founder of Amazon.com, Jeffrey P. Bezos, in a deal that has shocked the industry.

Donald E. Graham, chairman and chief executive of The Washington Post Company, and the third generation of the Graham family to lead the paper, told the staff about the sale late Monday afternoon. They had gathered together in the newspaper’s auditorium at the behest of the publisher, Katharine Weymouth, his niece.

“I, along with Katharine Weymouth and our board of directors, decided to sell only after years of familiar newspaper-industry challenges made us wonder if there might be another owner who would be better for the Post (after a transaction that would be in the best interest of our shareholders),” Mr. Graham said in a written statement.

In the auditorium, he closed his remarks by saying that nobody in the room should be sad — except, he said, “for me.”