The Tribune Tower, center, home of the Chicago Tribune newspaper, is near the Chicago River in downtown Chicago. (Tannen Maury/European Pressphoto Agency)

The biggest newspaper publisher in the United States has dropped its bid to buy the publisher of the Chicago Tribune and Los Angeles Times, marking an abrupt end to a chaotic corporate pursuit and casting further doubt on the country’s struggling print-news industry.

Gannett, the publisher of USA Today and dozens of other media outlets, said Tuesday it had after six months “determined not to pursue an acquisition” of Tronc, the publishing giant that changed its name in June from Tribune Publishing.

Lenders that had agreed to back the takeover balked in recent days after new data emerged showing deep losses in the print-advertising revenue of Gannett, which has sought to weather the industry’s advertising and subscription downturns by buying up papers in America’s major markets.

Tronc, which had previously rejected two Gannett bids, said in a statement Tuesday that Gannett had “decided to abruptly terminate discussions” and that Tronc shareholders had previously voiced “serious doubts about Gannett’s ability to finance a transaction.”

A Gannett spokesman said the company “had a number of financing options available” but that “in the end the terms were not acceptable.” The company chose to end discussions, the spokesman added, after considering the deal’s value to shareholders and “whether the terms make sense for the company.”

The merger was proposed as a salve for two companies scarred by the dramatic downfalls of print advertising in a new age of online journalism. But the deal’s collapse has highlighted growing worries over the long-term health of newspapers across the U.S.

Ad spending for print newspapers is expected to hit $12 billion this year, having fallen 75 percent since the industry’s $49 billion peak in 2005, data from industry researcher Magna Global show. That revenue is expected to plunge even further, to $6 billion, by 2020.

Publishers have increasingly sought to offset their weak business in print advertising by focusing more on digital subscriptions and circulation. Tronc, though, started late and has struggled to catch up. Tronc doubled its digital base over the last year, to more than 116,000 digital subscribers, but still counts less than 10 percent of the 1.3 million digital subscribers for the New York Times.

Tronc’s stock price, which soared when the negotiations were first announced in April, plunged 12 percent on Tuesday following news of the merger’s breakdown. Gannett shares slid more than 2 percent.

Tronc has sought to shake off its decades-old print legacy and become, as the company said in June, “a content curation and monetization company,” using “new artificial intelligence technology” and thousands of videos a day to bring in new customers and reinvigorate advertising sales.

But the company has also become infamous for its internal turmoil, including a controversial division of its print and broadcast operations, leadership shake-ups and one of the media business’ biggest bankruptcies.

Gannett has for years pushed aggressively to fold smaller papers into its ranks in hopes of boosting subscription revenue and streamlining operations, including the design and copy desks, which now often cover multiple news outlets from central, consolidated hubs.

The publisher has also been criticized for seeking to cut its way to prosperity, including through thousands of layoffs in its newsrooms and publishing operations nationwide. The McLean, Va.-based company said last week it would lay off another 2 percent of its 19,000-employee workforce.

Gannett papers, including the Detroit Free Press and Arizona Republic, make up about 12 percent of the country’s daily newspaper circulation, while Tronc papers such as the Baltimore Sun make up roughly 5 percent, data from the Alliance for Audited Media show. But a broad shift to digital is underway: Roughly 65 percent of USA Today’s revenue now come from digital advertising.

The deal’s dissolution, analysts said, will likely not change publishers’ strategy to survive through gobbling up big peers.

“Gannett has been viewed as the consolidator in the industry … and if there is an opportunity to get back to look at (Tronc) again, I think they will,” said Michael Kupinski, an analyst with Noble Financial Capital Markets.

“In the past, a lot of the small-to-medium-sized newspapers were viewed as the safe haven,” Kupinski said. “Now, in order to transition to the digital transformation of the newspaper industry, companies are looking at larger markets to grab larger audiences and national advertisers.”