No managers were available to speak Sunday about the apology or Chen's detention, said a man who answered the phone in the New Express's editorial department.
Chen's detention had caused an uproar among media professionals, who worry police are overstepping their legal jurisdiction in criminalizing civil disputes.
Legal scholars also voiced concerns about state media airing the confession of a suspect before a court hears the case. Chen has not been charged, as police are still investigating the case.
The New Express said Sunday it would take the incident as a warning, rectify existing problems and strengthen management of its editorial staff, including requiring them to abide by the law and follow journalistic ethics. The apology was a small part of its front page, the main story a football story, according to a picture of its front page uploaded to its website.
CCTV said Saturday that Chen ran more than 10 news articles between September 2012 and August 2013 with fabricated facts saying there had been losses of state assets, abnormal sales practices and false financial reporting by Zoomlion, which caused widespread criticism of the company and resulted in its stock price falling after one particularly damaging report.
Chen said a middleman bribed him to run the stories and that he filed the stories without verifying them. The middleman was not named.
Chen said he was given 500,000 yuan ($80,000) to report Zoomlion to regulatory agencies in Beijing and Hong Kong.
The Hunan provincial government owns one-sixth of Zoomlion and is its largest shareholder. Zoomlion filed the police report against Chen in September.