PETROLIA — Contract talks between negotiators for Indspec Chemical and the company’s locked-out union are to resume Thursday.

The two sides met for several hours Friday at a Butler Township motel. While no new offers were exchanged, negotiators agreed to return to the bargaining table this week.

“I’m encouraged to the extent we had a nice dialogue with (the company), and (the union) was able to talk in more broader terms about specific issues important to us,” James Woodward, a staff representative with United Steelworkers District 10, said Monday.

Indspec, a subsidiary of Los Angeles-based Occidental Petroleum Corp., locked out 175 full-time workers after their union rebuffed company demands for contract changes.

The employees have been manning a picket line outside the chemical plant since April 5, when their three-year contract expired.

The company rejected a union proposal that sought to keep workers on the job under the terms of the former contract during negotiations for a new pact.

A telephone call to Gil Gomez, director of human resources for Occidental Petroleum at its office in Dallas, and chief negotiator for the company in the ongoing talks, was not returned Monday.

But in a statement issued April 7, Indspec said the contract concessions it was seeking from workers were essential to compete financially with global competitors.

Both sides have kept details of the negotiations close to the vest. But Woodward on Monday said one key sticking point is a company demand that seeks to increase workers’ insurance contributions.

He said employees paid an average of 12 percent of health insurance premiums under the old pact.

“They want to increase that to 15 percent,” Woodward said of the company.

The rank-and-file, he said, also is opposed to company proposals seeking changes in employee benefits, including holiday time, and work force restructuring.

Woodward admitted both sides are at loggerheads over “what people get paid when they’re called out, shift differential and Sunday premiums.”

He declined to elaborate.

Woodward said he believed union negotiators conveyed their concerns with company counterparts on Friday.

He expected the company to present a contract offer, in writing, at this week’s meeting. He said the meeting Thursday could continue on Friday if talks go well.