Leon Black wants to be a newspaper magnate. The New...

The expected buyer of the Los Angeles Times is facing a deadline.

Dr. Patrick Soon-Shiong, a California health care mogul, must soon decide whether to complete his $500 million purchase of the Times and San Diego Union-Tribune — a price many believe is way too rich — or walk away, The Post has learned.

For the last month, Soon-Shiong has attempted to walk a more undefined route — delaying closing on the deal despite winning regulatory approval on March 5 while perhaps weighing a move to seek a cut in the purchase price.

Tronc, the LA Times owner, seems to be against a price cut, sources said.

While the mogul has dithered, at least two prospective buyers for all of Tronc have emerged, creating some urgency, sources said.

One suitor is Japan-based SoftBank, a source on Monday confirmed to The Post.

Led by Masayoshi Son, SoftBank — which last year bought the Gatehouse newspaper chain — is interested in making a bid for Tronc, which also owns the Chicago Tribune and the New York Daily News.

Softbank’s interest was first reported by Axios.

The SoftBank news caused Tronc’s stock to jump to $19, up 11 percent on the day.

The Post reported exclusively on Thursday that Leon Black’s Apollo Global Management is eyeing Tronc, the company formerly known as Tribune Publishing. One source said that those talks have been quietly underway for months.

Soon-Shiong, meanwhile, has been trying to give the impression that he will be the new owner of the Times, perhaps to scare off suitors.

In a meeting that Soon-Shiong called on Friday with hundreds of LA Times staffers, he insisted that the talks had not stalled and he was merely negotiating to extract the paper from the Tronc network and sever its ties to Chicago. Even though he had not taken title to the California dailies, he told staffers he was going to move the paper from downtown LA to El Segundo, a suburb about 20 miles away.

Tronc had not given him permission to speak, and Soon-Shiong rented space in the LA Times building to address staffers.

Soon-Shiong, a onetime ally of former Tronc Chairman Michael Ferro, had feuded with him over the past two years. Some industry sources were speculating that Soon-Shiong, Tronc’s second-largest shareholder, could still make a run at the entire company. Even after the run-up in Tronc shares, the publisher is valued at $776 million, including equity and debt.

Ferro probably would have thwarted a takeover of the entire company by his acrimonious rival, but the chairman revealed in an SEC filing late Friday that he is selling his 26-percent stake to McCormick Media, a trust run by the family that once owned the Chicago Tribune, for $208.6 million or $23 a share.

Ferro is making a hefty profit. The Chicago Tribune said that deal was only hatched after McCormick Media approached Ferro in the past several weeks.

Tronc declined to comment.

Soon-Shiong and officials with Gatehouse could not be reached for comment. Gannett, which broke off talks to buy Tronc in November 2016, also is considered a potential buyer in the current scenario.