Harte said most of the 58 job cuts affect workers in the circulation department, where the newspaper has made "substantial changes" by adding new technology and changing the way it handles delivery of the newspaper.
The cuts don't extend to workers in the newsroom or in advertising.
The Star Tribune has been wrestling with an industrywide problem of declining circulation numbers and ad revenues, as competition stiffens with online news sources.
The paper shaved 140 jobs in 2007 through voluntary buyouts. But the cost reductions were not enough, Harte told employees.
"At the time, we thought these steps would be sufficient to stabilize the business, but our advertising revenue projections were too optimistic," Harte wrote.
Classified ads for real estate, autos, and jobs have fared even worse than the overall economy, he wrote.
David Shanen co-chairs the Newspaper Guild unit at the Star Tribune, which represents three of the workers affected by the cuts.
Shanen says seven jobs in the photography department were eliminated last week as well. He says the guild is disappointed about the latest moves.
"The company had hired a consulting firm to work with the union to try to get more buy-in as we make moves in the future. So far, we haven't been asked to weigh in or discuss any of the last couple moves they've made," says Shanen.
In addition to the job cuts, the Star Tribune is freezing wages of independent employees and senior executives. The paper has about 600 such workers.
Those who lose their jobs will get the same severance benefits offered in a round of buyouts last year.
(The Associated Press contributed to this report)