Parties in one of the two lawsuits facing embattled breast implant manufacturer Sientra are in negotiations to settle the case.

Documents dated Sept. 2 state three plaintiffs including the Oklahoma Police Pension and Retirement System are negotiating a settlement with Goleta-based Sientra in a lawsuit in state court in San Mateo. At an Aug. 23 hearing, Judge Marie Weiner set a deadline of Sept. 2 for the parties to settle the case.

A Sept 2 filing with the court says parties are still in discussions, but discussions have been hampered because “in part to the unavailability of persons needed to participate in such discussions.”

In the document, the parties requested and agreed to continue discussions and set a new deadline of Sept. 15 to reach a settlement. The next hearing in the case is scheduled for Sept. 23.

The case alleges Sientra knew about a looming suspension of implants made by its Brazilian manufacturer Silimed before holding a Sept. 23, 2015 second-public offering. The offering netted Sientra about $66 million, but its stock quickly plunged from $20.58 to $9.70 per share the next day.

In June, Judge James Otero declined to dismiss a similar case in federal court in Los Angeles filed by plaintiffs that also allege similar allegations about the timing of the offering.

Founder and former-CEO Hani Zeini resigned as the company’s CEO in November and resigned from the company’s board of directors in February.

At a June shareholder meeting, CEO Jeffrey Nugent said the situation is being reviewed. Chief Financial Officer Matthew Pigeon said at the meeting the company could not answer questions regarding either lawsuit because of the ongoing litigation.

• Contact Philip Joens at pjoens@pacbiztimes.com.