It was an offer he could refuse.

A Long Island construction company owner hired a hitman to knock off a bitter business rival — only to have the would-be killer get cold feet and rat him out to the cops, Nassau County prosecutors said.

Navdeep Singh, 48, allegedly offered the contract killer $100,000 and a 10-acre plot of land in India to knock off his nemesis during an ongoing bitter legal battle between the two — but is instead now facing felony conspiracy and criminal solicitation charges.

“The allegations against Navdeep Singh are deeply disturbing,” Nassau County District Attorney Anne Donnelly said during a press briefing Monday.

“Because of a years-long dispute with a former business associate and multi-million dollar pending civil litigation between their two construction companies, this defendant allegedly decided to hatch a plot to have his rival kidnapped and murdered,” Donnelly said.

Prosecutors said Singh, the owner of Gravity Construction Corp., had a longstanding business relationship with the target of his alleged murder-for-hire plot, but had a falling out with the person two years ago.

The two are currently embroiled in a nasty civil lawsuit.

“It is unfathomable the lengths to which this defendant was allegedly willing to go,” she added.

The beef began after Singh’s company was kicked off a construction job managed by his adversary.

Singh is accused of reaching out to the would-be hitman on May 29 to kidnap, torture and kill the rival. As part of the deal, Singh wanted to see photos of the man’s head and torso to confirm the deed was done.

He allegedly paid the hire $7,000 up front, an advance on the $100,000 contract that included a plot of land in India after the killing was completed, Donnelly said at the briefing.

Singh even cased the intended victim’s house to help the contract killer complete the job.

The man accepted the job but then “immediately” chickened out and ran to the cops to expose the plot, according to prosecutors. Singh was subsequently arrested Saturday and arraigned on Sunday.

He was ordered held on $1 million cash bail or a bond of up to $5 million, prosecutors said.

“This was a very dangerous situation,” Nassau County Police Commissioner Patrick Ryder said at Monday’s press briefing.

“Thanks to the hard work of our district attorney squad working in partnership with DA Anne Donnelly and her tenacious prosecutors we prevented what would have been a tragedy — settling a business dispute with murder.”