Athenahealth shares tumbled Tuesday after The Post reported that the healthcare company’s effort to go private has hit a snag.

Billionaire Paul Singer’s Elliott Management, which had proposed taking the company private at $160 a share in May, has backed off and is now considering a lower bid, sources told The Post on Monday.

The deadline for final bids, which was initially set for Sept. 17, has been extended by 10 days.

Shares plunged 6.9 percent to $133.17 in mid-morning trades as Wall Street digested a slowdown in the process.

Athenahealth’s shares, which had traded around $150 earlier this month, had been supported by Elliott’s interest, analysts and RBC Capital said in a note Tuesday.

The $35 billion hedge fund is still working with private equity firm Bain Capital on a bid — although one that may be lower than $160 a share.

There is at least one other suitor looking at Athenahealth, sources said. Earlier this month The Post reported that Cerner Corp. and UnitedHealthcare — both seen to be logical strategic buyers — are no longer interested.