The New York Sun, the six-year-old newspaper with a conservative mind-set, announced on Monday that it would close after publishing Tuesday’s issue.

The Sun’s president and editor, Seth Lipsky, said a three-week search for new financial backers had failed. Mr. Lipsky announced on Sept. 4, in a front-page “Letter From the Editor,” that The Sun would shut down by the end of the month unless it raised new money.

Mr. Lipsky told editors and reporters who gathered on Monday afternoon in The Sun’s loftlike newsroom in Lower Manhattan that the shutdown was “a logical decision following a hardheaded assessment of our chances of meeting our goal of profitable publication in the near future.”

As he spoke, the stock market was diving toward the largest one-day point loss in the history of the Dow Jones Industrial Average. “Among other problems that we faced,” he said, “was the fact that this month, not to mention this week, has been one of the worst in a century in which to be trying to raise capital, and in the end we were out not only of money but time.”