By Brian Stelter, NPR

BOSTON — NPR is ending the 21-year-old call-in radio show “Talk of the Nation” and encouraging local stations to replace it with an expanded version of “Here and Now,” an afternoon newscast that is produced here.

The plan, announced Friday, is the product of discussions that began more than two years ago between NPR and some of its biggest member stations. The stations wanted a magazine-style news show at the middle of the day, something along the lines of “Morning Edition” and “All Things Considered,” the two bookends of most stations’ weekday schedules.

“Here and Now” fits that description. The program, produced by Boston University’s WBUR, started locally in 1997 and began to expand nationally in 2001. Until now, it has been distributed by a rival programmer, Public Radio International, but in the summer it will start to be distributed by NPR instead.

NPR will partner with WBUR to turn the one-hour “Here and Now” into a two-hour show, with contributions from NPR News staff and other local stations. A co-host, Jeremy Hobson, will join the current host of the program, Robin Young.

The partnership marks the first time that NPR, a national supplier of newscasts and shows, has linked arms with a station in this way. “Together, we’re addressing both what the audience is looking for and what member stations have been looking for,” said Kinsey Wilson, the chief content officer for NPR.

He declined to comment on the specifics of the financial arrangement, but said, “We’re confident that by partnering together we can make this both an editorial and a financial success.”

The longer version of “Here and Now” will start July 1, immediately after “Talk of the Nation” bows out. “Talk” is a radio fixture from 2 to 4pm Eastern time, broadcast by 407 stations and reaching 3.53 million listeners a week, according to NPR. (That total counts all the people who hear the program at any point during the week.) It mixes long-form interviews with calls and emails from listeners.

Neal Conan, an NPR reporter and anchor since 1977 and the host of “Talk” since 2001, will “step away from the rigors of daily journalism,” NPR said in a statement.

“They set the standard in many ways for high-quality call-in talk,” Wilson said about “Talk of the Nation.”

The Friday version of “Talk of the Nation” — “Science Friday with Ira Flatow” — will continue to be distributed by NPR, the organization said.

Wilson said the decision to end “Talk” came out of the discussions with WBUR about a partnership.

Local stations continue to produce their own call-in shows, he said, and some are carried nationally, like “On Point,” which is also produced by WBUR. But the change announced Friday is a move away from opinion and toward straightforward storytelling.

Among local stations, there has been a “hunger for a stronger news presence in the middle of the day,” said Charlie Kravetz, the general manager of WBUR, who helped organize a meeting of station directors about midday news back in 2010.

“Here and Now” is broadcast by 182 stations now, but many of them are small; of the 25 biggest radio markets in the country, only eight currently carry it. Partly for that reason, it reaches about 1.35 million listeners a week, far fewer than “Talk of the Nation.” A spokeswoman for NPR noted that its audience has grown about 11 percent from a year earlier.

NPR will begin to pitch “Here and Now” to stations on Friday morning. While “I’m sure we won’t convince everyone,” Mr. Wilson said, “our goal is to convince a large number of stations that carry ‘Talk of the Nation’ to carry ‘Here and Now.’”

The arrangement strengthens NPR’s ability to react to breaking news situations. The two-hour program will be produced between noon and 2pm Eastern, and then updated as needed until 4pm for stations that choose to carry it later in the afternoon. This way, “Here and Now” can be a bridge from “Morning Edition,” which starts at 5am in some markets but is updated until noon, to “All Things Considered,” which starts at 4pm.

“This will essentially provide us the ability to go live, if we need to, from 5 in the morning until 10 o’clock at night,” Wilson said.

NPR produced a midday news magazine called “Day to Day” in the mid 2000s, but it was canceled in 2009.

Kravetz said, “A central part of our plan is to tap into a lot of the public radio stations across the country that are doing wonderful journalism that never gets heard outside of their markets.”

For the three months that “Talk” is still on, NPR and WBUR will hire new staff members for the expansion. Mr. Hobson, currently the host of public radio’s “Marketplace Morning Report,” distributed by American Public Media, will come on board and Meghna Chakrabarti, a local host in Boston, will be the backup host.