The city-state agency that manages Guaranteed Rate Field is out more than $1.2 million and has suspended its chief executive after canceling a concert it planned to host at the stadium, the Chicago Sun-Times has learned.

The Illinois Sports Facilities Authority spent about $1.6 million “toward retaining talent” for a concert expected to draw 30,000 people to Guaranteed Rate Field on Sept. 16, according to top ISFA officials and agency records obtained by the Sun-Times.

But the stadium authority called off the “Get In It Musicfest,” and officials say they have been able to get back only about $350,000 of what they spent to try to put on the show.

ISFA’s board chairman and its top lawyer told the Sun-Times the agency has hired a law firm to investigate what happened after the agency partnered with an East Coast company to promote the concert.

IFSA general counsel Maria Saldana says the company, Mike Daddy Unlimited, promised — but failed — to sign Sean “Diddy” Combs to perform at the concert here.

The stadium authority then hired another company, which secured the services of some artists, she says. But delays in booking the acts “impacted ticket sales, ultimately resulting in ISFA deciding to cancel the event,” according to Saldana.

Manny Sanchez, the Chicago lawyer who heads the ISFA board, said officials hired the Mayer Brown LLP law firm to investigate.

“We don’t think the co-promoters lived up to their end of the bargain,” Sanchez said.

The president of Mount Vernon, N.Y.-based Mike Daddy Unlimited, Michael Evans, did not reply to repeated requests for comment.

ISFA CEO Anthony O’Neill, who signed the deal with Mike Daddy Unlimited, has been put on paid administrative leave pending the outcome of the investigation “into the circumstances surrounding these events,” Saldana said. O’Neill did not return messages for comment.

The stadium authority was created in 1987 to build and manage the Chicago White Sox stadium, now known as Guaranteed Rate Field, and it also borrowed hundreds of millions of dollars in 2001 to finance the renovation of Soldier Field. ISFA has a budget of about $60 million a year — most of it coming from Chicago hotel tax revenues. The city and state also each give the agency $5 million a year.

The ISFA board is made up of appointees chosen by the governor and the mayor. In recent years, officials have tried to increase revenues by bringing events to the stadium on dates when the venue isn’t being used by the White Sox.

Documents obtained by the Sun-Times show O’Neill signed a contract with Mike Daddy Unlimited on behalf of his agency on May 3. Under the deal, ISFA hired Mike Daddy Unlimited “to act as its exclusive consultant with respect to the procurement and booking of all talent and live entertainment” for the show.

The stadium authority and the company were supposed to contribute $650,000 each toward the $1.3 million budget for performer fees. Mike Daddy Unlimited “shall be solely responsible for all payments to the performers,” records show.

Mike Daddy Unlimited was contractually obligated to book Combs and Joseph “Fat Joe” Cartagena as headline acts and would “make best efforts to procure and book other feature performers,” such as former Black Eyed Peas singer Fergie, according to the five-page agreement.

Saldana, the ISFA lawyer, says Mike Daddy Unlimited never paid its $650,000 share of the budget for performer fees, did not sign Combs or an alternative headline act and “failed to provide a full accounting” of what it did with money it got from the stadium agency.

“Even where MDU was able to secure performers, MDU failed to provide ISFA with the amounts to be paid to the artists — whiting out amounts before providing copies of contracts to ISFA,” Saldana said.

She said Mike Daddy Unlimited told the agency it couldn’t tell officials what it was paying the performers because of non-disclosure agreements, “which MDU never provided to ISFA.”

Another booking agency, Patriot Artists of New York, was hired to act on ISFA’s behalf in securing talent for the Get In It Musicfest, records show.

By July 27, the company had signed deals with Lupe Fiasco, Macklemore and other performers, according to ISFA documents. Patriot Artists was entitled to collect a 10 percent fee on what was paid to those artists.

In addition to the $650,000 that the stadium authority originally shelled out, ISFA paid the $650,000 share of the fees that Mike Daddy Unlimited was supposed to pay, Saldana said.

She said ISFA board members approved the initial contract with Mike Daddy Unlimited “via email with intent to ratify at a subsequent board meeting.” But she said, “That was never done.”

And Saldana added that the board never approved spending more than the initial investment of $650,000.

The change in promoters, she said, further drove up the cost of paying the artists.

But the total outlay of about $1.6 million apparently was too little, too late to save the Get In It Musicfest.

“The event was canceled due to slow ticket sales,” Saldana says. “ISFA contributed about $1.6 million toward retaining talent for the concert and has recouped approximately $350,000 to date.”

Concert documents indicate it could be impossible to get much of the rest of the money back.

In a June 15 contract on the letterhead of the Creative Artists Agency of Los Angeles, the Fifth Harmony girl group was to be immediately paid $300,000 to perform in Chicago last month.

“In the event that the engagement does not occur, not as a result of artist’s sole action, artist will nevertheless be paid the full guarantee,” the document states.

The stadium authority had hoped to put on an event such as last year’s Magnificent Coloring Day concert, which featured Chance the Rapper and drew nearly 48,000 fans to Guaranteed Rate Field.

ISFA was paid $188,000 to rent out Guaranteed Rate Field for that event in 2016 but wanted to take a chance to make more money as an organizer of the concert this year, selling tickets for $35 to $150, officials said.

“Last year, we were landlords,” says Sanchez, who was appointed to the ISFA board by Gov. Bruce Rauner. “This year, we were persuaded to be co-promoters. Unfortunately, it didn’t work out.”

The stadium agency was not the only loser in the canceled concert fiasco.

Under the contract for the event, ISFA and Mike Daddy Unlimited had agreed that a $3 surcharge would be added to each ticket sold and that money would go to a charitable cause.

Sanchez and Saldana said the charitable contribution would have gone to an anti-violence group Get In Chicago. The group’s board includes businessman Jim Reynolds — who also sits on the ISFA board, as an appointee of Mayor Rahm Emanuel. Reynolds did not return calls seeking comment.