INDIANAPOLIS — Negotiations to keep the popular Indiana-Kentucky basketball series alive have stalled for the second time in a month and there seems to be little chance of reviving it.

Indiana athletic director Fred Glass announced May 3 that the series, an annual tradition since 1969, would end because the two schools could not agree on whether to play the games at neutral sites or on the two campuses.

According to a letter obtained Wednesday by The Associated Press, the two athletic directors reopened negotiations May 10. Two weeks later, the letter said, Kentucky rejected Indiana’s offer for a four-year extension that would have put the first two games at Lucas Oil Stadium, which Wildcats coach John Calipari wanted. The third game would have been played at Kentucky and the fourth at Indiana.

“I’m disappointed Kentucky rejected what I thought was a compromise that would address everyone’s concerns,” Glass told The Associated Press. “(Coach) Tom (Crean) and I felt like we tried to be accommodating to Kentucky.”

Kentucky had a variety of concerns, some of which were explained in the letter dated May 25.

Wildcats AD Mitch Barnhart said he didn’t receive Glass’ letter until Wednesday and expressed additional concerns in a statement released by the athletic department.

“I informed Fred that we were disappointed that our previous verbal agreement for a two-year neutral site contract was off the table, but we would consider the new proposal,” Barnhart said. “I also noted there were some challenges in our current schedule that were not present prior to Indiana’s announcement on May 3 that they were moving on with their schedule for 2012-13.”

The Wildcats had already scheduled a game for the second Saturday in December, when Indiana and Kentucky traditionally meet. Moving the Portland game from Dec. 8 would have cost Kentucky $100,000.

So Glass offered to play the game on Dec. 5, when Kentucky had scheduled a contest against Samford, or to split the cost of the Portland buyout. Glass also said he would assist in dealing with Samford if necessary and even offered to move Indiana’s Dec. 22 game to free up a date for the border-state clash.

When Calipari announced on Twitter that Kentucky was pursuing a new “non-traditional” scheduling philosophy, Glass had his answer.

Glass wrote in the letter that Kentucky spokesman DeWayne Peevy officially rejected the compromise in a phone call May 24.

Both schools have historical arguments on their side.

The games rotated between Freedom Hall in Louisville and the Hoosier/RCA Dome in Indianapolis from 1991 through 2005. That’s when the two schools moved their games back to campus sites, where the rivalry’s regular-season games were played exclusively from 1976 through 1986.

Indiana doesn’t want to add another non-home game to a schedule that already includes the annual Crossroads Classic in Indy, a road game every other year for the ACC-Big Ten Challenge and multiple in games in tournaments contested in Hawaii, Alaska or other places. While some believe the two schools could make more money by playing in larger, off-campus arenas, Indiana believes neutral sites would not create the same atmosphere.

“Mitch and I had pretty specific conversations about a neutral site at Indianapolis and a neutral site at Louisville, most likely Lucas Oil Stadium and Freedom Hall,” Glass said. “Tom and I didn’t feel comfortable about freezing out our students or our season-ticket holders. Since John Calipari said he would be willing to do the Lucas-Lucas deal, that’s where our compromise started, and we felt it was only fair to let Kentucky to have the third game with the fourth game coming back to Indiana because that would give next year’s (incoming) students an opportunity to see the game on campus.”

Kentucky still said no thanks because, Glass wrote, the Wildcats did not want to sign a deal that was longer than two years.

“If this compromise wasn’t acceptable, I don’t know what would be,” Glass said.

What happens next?

Kentucky is reviving its series with North Carolina series and Calipari has talked about a series with national powerhouse Duke. The Wildcats also have signed a two-year deal to play Baylor, including a men’s-women’s doubleheader in Dallas.

Speculation around Indiana has focused on finding another big-name opponent to replace Kentucky, perhaps Kansas or Louisville, on the schedule. Glass declined to talk specifically about Kansas, but acknowledged it’s time for the Hoosiers to start looking for a team to replace Kentucky.

Last year, Kentucky and Indiana played two of the college basketball’s most entertaining games.

Indiana handed the Wildcats their only regular-season loss on a buzzer-beating 3-pointer from Christian Watford that set off a wild celebration and sent students rushing onto the court. Kentucky went on to win the national championship, beating Indiana 102-90 in the regional semifinals.

“We’ve really been focused on trying to keep this series going. That would be our first choice. Now that they’ve rejected our compromise, we have to move on,” Glass said.

He added: “I think the idea that has, frankly, been posited by some people who think cooler heads can prevail has been proved basically inaccurate. I think we provided a compromise that to most people would be pretty acceptable.”

But Kentucky is completely ruling out the possibility of a game this season.

Barnhart noted the Wildcats have kept Dec. 15 and Dec. 22 open on the schedule for a possible game against Indiana, that Lucas Oil Stadium is available and that he’d still like to see the game played on one of those dates.

“In the best interest of our fans, I would hope we can come to a conclusion to continue this storied series this December,” Barnhart said.