Marimow, who also served as the Inquirer's editor from 2006 to 2010, declined to comment on the decision. Former editor Stan Wischnowski has been named acting editor.
The current owners the fifth buyers in six years include influential New Jersey Democrat George Norcross III and former New Jersey Nets owner Lewis Katz. Hall would not say whether they signed off on the firing but said the decision was his alone and came after weeks of talks on editorial changes.
"There's been a lot of discussions about this for a month. It shouldn't be surprising," Hall said.
Norcross, Katz, cable TV mogul H.F. "Gerry" Lenfest and others formed Interstate General Media to buy the newspaper last year along with the Philadelphia Daily News and the Philly.com website for about $55 million. That's a fraction of the $515 million sale price in 2006, and the $139 million creditors paid at a 2010 bankruptcy auction.
Norcross' daughter, Lexie, is a company executive overseeing Philly.com, which often highlights entertainment news and other lighter fare, along with hard news.
The company also owns subscription-based websites for each newspaper. That setup has caused concern among some reporters, as stories put behind the newspaper pay walls can be found on Philly.com for free.
Hall agreed that the model needed to be reviewed.
"We will probably clarify our strategy in the near future, so everybody's on the same wavelength," he said.
The Inquirer won the Pulitzer for public service last year for a series on school violence in Philadelphia.