The owners of the Forum filed a fraud and breach-of-contract lawsuit against Inglewood this week over the city’s negotiations with the Los Angeles Clippers for a proposed new arena about 1.5 miles away from the famed venue.

The Los Angeles Superior Court lawsuit accuses Mayor James Butts of deceiving MSG Forum officials into surrendering a long-term lease and purchase option for 15 acres of city-owned land used for overflow parking by claiming it was needed for a planned “technology park.’’ But the city instead engaged in secret talks with the Clippers about a possible new arena “using the very same land MSG Forum had leased for parking,’’ according to the lawsuit.

MSG officials contend in the suit that the city’s negotiations to build a competitive arena violate terms of the Forum’s contracts with Inglewood that bar the city from taking any actions that would cause “a material adverse impact on the use, operations, functionality or economic competitiveness of the Forum.’’

“Unfortunately, the shocking and outrageous conduct of the mayor, city officials and others have forced us to seek accountability in the courts in order to protect the Forum,’’ said Marvin Putnam, attorney for MSG Forum.

There was no immediate response to a request for comment from the city. Last year, when Forum officials first raised objections to the Clippers negotiations, Butts said he was confident the parties could resolve their differences.

“The city of Inglewood cherishes its relationship with The Madison Square Garden Company and Live Nation,’’ Butts said. “Working together, we have seen the Forum become one of the top concert venues in the country.

“We disagree on the city’s right to self-determination and the scope of that right,’’ Butts said. “The Inglewood City Council’s first responsibility is to its residents and their quality of life while ensuring continued progress, opportunities for employment and improved public safety.

“In the end, I believe that we will be able to come together and find an amicable resolution,’’ he said. “In the meantime, life goes on unabated for both the Forum and the city of Inglewood.’’

The lawsuit details a timeline of discussions between Forum officials and Butts, contending it was MSG Forum that initially discussed the possibility of moving the Clippers to the Forum when the team’s lease at Staples Center expires, but that proposal never advanced. But the suit accuses Butts of then engaging in secret talks with the team to build a separate arena.

The suit also contends that in January of 2017, Butts asked Forum officials not to use his official city email account for communications, directing them instead to use his personal Gmail account in an apparent effort to prevent “a paper trail evidencing his bad acts.’’

The Inglewood City Council in June of 2017 approved an exclusive negotiating agreement with the Clippers for possible construction of an arena on 22 acres of land that includes the property previously leased by the Forum.

The lawsuit cites city documents indicating that the proposed Clippers arena could host 100 to 150 “family shows, concerts, conventions and corporate events each year.’’

“This competing arena would be located less than a mile and a half from the Forum property on Prairie Avenue — in bird’s eye view from the Forum’s famed balcony and across the street from the Hollywood Park property and Hollywood Park Casino,’’ according to the lawsuit.

The lawsuit seeks a court order blocking further talks between the city and the Clippers, reinstatement of the Forum’s parking lease on the proposed arena property and unspecified compensatory and punitive damages.

Clippers owner Steve Ballmer said previously he wants to move the NBA team from Staples Center, which it shares with the Los Angeles Lakers and the National Hockey League’s Los Angeles Kings, to a new state-of-the-art facility.

The Clippers’ Staples Center lease is up in 2024.

Inglewood’s agreement with Ballmer, which was secured by a $1.5 million payment to the city, gives the team and the city three years to negotiate for the proposed 18,000- to 20,000-seat arena at the corner of Century Boulevard and Yukon Avenue.