Hearst on Monday said the Seattle Post-Intelligencer would become the largest newspaper ever to move to an online-only format. The move leaves the Tuesday issue as the last paper copy and ends the 146-year history of the physical edition. Its owners describe the shift as the result of “extremely difficult circumstances” for the company’s finances and after unsuccessfully trying to sell the Post-Intelligencer to another company since January 9th. To make up for the absence of the newspaper, Hearst said it would ramp up online advertising by creating a dedicated team that would pick up local advertising. It also draws on Ask.com, Google, Kaango, MSN and Yahoo for its larger online ad plans.