In a bit of corporate synergy, Time Warner is planning to dip into one of its strongest cable channels, HBO, to help revive the fortunes of one of its weakest, CNN.

Jeffrey Roth/HBO

As part of Time Warner’s attempt to reinvigorate its 24-hour cable news channel, which recently suffered from its worst ratings slump in 20 years, the company said it had encouraged CNN to look for creative ways to incorporate HBO’s sports and documentaries into its lineup of news programs.

On Sept. 1, CNN will broadcast “41,” an HBO documentary about George H. W. Bush that premiered on the pay-cable channel in June. On Sept. 2, the network will introduce the 2009 HBO documentary “Teddy: In His Own Words” about Senator Edward M. Kennedy.

The strategy fits into a broader effort by CNN to develop unscripted series to complement its news reports, particularly on late nights and weekends.

CNN said Thursday that it had recruited the documentarian Morgan Spurlock, best known for his 2004 Oscar-nominated film “Super Size Me,” to host and produce a series called “Inside Man.” The show will have its debut in April 2013 and will follow Mr. Spurlock each week as he immerses himself into a niche of American life, including migrant farm workers and marijuana growers.

In May, CNN said it had hired the chef Anthony Bourdain to host a weekend program, that is still unnamed, that will be shot on location as Mr. Bourdain explores food, culture and travel. “I’m not gonna barbecue in ‘The Situation Room’ with Wolf Blitzer,” Mr. Bourdain told the Hollywood Reporter.

CNN said Mr. Bourdain’s program would be broadcast as a weekend block with Mr. Spurlock’s series, an approach that has helped CNN’s cable news competitors. Both MSNBC and Fox News mix reporting with documentary series: “Lockup,” on MSNBC, is about life inside prisons, and the military history program “War Stories” is hosted by Oliver North on Fox.

“We’re moving toward doing more original long-form programming on the weekends, and obviously a lot of stuff the HBO documentary unit does fit in nicely with that,” said Mark Whitaker, executive vice president of CNN Worldwide.

CNN has dipped into HBO’s trove of documentaries and sports programming before, with “Citizen USA,” about new American citizens, and “Triangle: Remembering the Fire,” about the fatal 1911 fire at the Triangle Waist Company in New York City.

In July, Time Warner said Jim Walton, president of CNN Worldwide, would step down at the end of the year. “CNN needs new thinking,” Mr. Walton said in an internal memorandum. “That starts with a new leader.”

Jeffrey L. Bewkes, chief executive of Time Warner, served as chairman and chief executive of HBO from 1995 to 2002, a period of strong growth.

Mr. Whitaker said Mr. Bewkes was not directly involved in CNN’s programming decisions, but “he has made it clear that he would love to see us all working together a little more.”

There is always a risk in broadcasting too many HBO films on a basic cable channel like CNN, since subscribers pay roughly $15 a month for access to those movies on the HBO channel, HBO on Demand and the HBO Go Web site and app.

Mr. Whitaker said documentaries were different from series like “True Blood” and “Game of Thrones,” in that HBO does not make them for ratings or to attract new subscribers, but for the prestige and critical attention documentaries bring.

“I think their view is that they’ve already made the investment and the filmmakers have made the investment and they’d like to see the work get more exposure,” Mr. Whitaker said. An HBO spokesman agreed.