Detroit ? Fighting to stay in business, Detroit’s two daily newspapers will radically change their relationship with readers by slashing home delivery to three days a week, printing small editions on other days and encouraging people to get information online.

The Detroit market is the largest in the country to undergo that transformation. But it reflects a calculation facing newspapers across the country, with print circulation dropping as readers increasingly get their news on the Internet.

By curtailing home delivery on certain days, the papers reduce printing, fuel and labor expenses for editions that tend to attract fewer advertisements.

The chief executive of Detroit Media Partnership, which runs the Detroit Free Press and The Detroit News, said the move announced Tuesday was not an experiment. He predicted it would succeed in keeping two papers alive.

“I don’t think we’re ever going back,” said David Hunke, who also is publisher of the Free Press.

If it fails, “I’m fired and I may have led two great institutions down the wrong path,” he said. “It’s a huge risk. It’s disruptive to folks. I understand that.”

But the newspapers, he said, can’t afford to wait. Detroit Media Partnership is losing millions of dollars this year, and Michigan has been hammered by home foreclosures, high unemployment and the near-collapse of the auto industry.

“We’re here because we’re fighting for our survival. … But we’re not doing this with our heads down,” Hunke said.

After the change, which takes effect in March, for $12 a month home subscribers will be able to get the Free Press delivered Thursday, Friday and Sunday. Or for that price a subscriber could get the News on Thursday and Friday, plus the Free Press on Sunday. The News does not publish a Sunday edition.

That subscription package — which is $1 to $2 less than current monthly rates — will also give people access to an online replica of the roughly 32-page editions of both papers that will be sold each day at newsstands. Both papers also will regularly update the news on their free Web sites, freep.com and detnews.com.

“Americans are reading with their feet. They’re walking over to the computer screen,” said Jonathan Wolman, the editor and publisher of the News, which is owned by MediaNews Group Inc. The Free Press is owned by Gannett Co.

Newsrooms will be spared layoffs but Detroit Media Partnership still expects to cut 9 percent of its work force of 2,151 employees; “hopefully” less, Hunke said.

Ron Renaud, secretary-treasurer of Teamsters Local 372, said he fears drivers and other delivery personnel will be hit the hardest. Talks with unions will start in January.