In an announcement today owner Trinity Mirror said the decision followed "an extensive review of its portfolio in the North West".
The company added that "there are no planned journalist redundancies as a consequence of this decision". On Twitter, editor Mark Thomas said that "all will be offered new roles at Trinity Mirror".
And the company statement added that "the Post will continue its respected coverage of Merseyside’s business community in a Post-branded section of the Liverpool Echo".
An article about the closure on the Post's website explained that "some key elements of the Post's business coverage are to continue in the pages of our sister title, the Liverpool Echo".
The newspaper made the move from daily to weekly back in January 2012, and introduced its e-edition for tablet devices just six months ago, a paid-for offering which launched with a monthly price-tag of £9.99.
Both the newspaper and e-edition will be released for the last time on Thursday 19 December, Trinity Mirror today confirmed.
In a statement, Steve Anderson, managing director for Trinity Mirror North-West, said "the Liverpool city region no longer generates the demand in terms of advertising or circulation, to sustain both the Post and the Liverpool Echo".
With the Liverpool Post removed from its portfolio, the publisher plans to "ramp up its publishing operation across the weekend with further investment in the Echo".
"’We are committed to retaining the best of the Post in the Echo," Anderson said. "We are also committed to the continued expansion of the Liverpool Echo and have exciting plans on the table for weekend publishing.
"The Echo is an extraordinary brand and we are thrilled to be expanding its reach and creating jobs as we do so."
Too many lovely, thoughtful messages to respond to individually, but on behalf of the team, thank you everyone.— Mark_Thomas (@Mark_Thomas) December 10, 2013
Responding to the news, Chris Morley, northern and Midlands organiser for the National Union of Journalists, described it as "a shocking blow to the city at a time when it needs champions".
He added that the union will be watching closely "to ensure the passing of the Post does not take with it journalists' jobs".