Just weeks after an agreement that reportedly averted a union strike, workers for natural gas provider ENSTAR took to a Midtown street corner Monday to do precisely that following a divided vote.

Dozens of employees were picketing outside ENSTAR’s headquarters at Spenard Road and 31st Avenue as of 11 a.m. Monday, watched by Anchorage Police Department officers. The line was generally quiet and peaceful outside the offices, which were closed for the day, but carried signs reading “ENSTAR Attacking Benefits” and “ENSTAR Bargains in Bad Faith.”

Chuck Dunnagan, the union’s general counsel, tells Channel 2 no end is in sight for the strike, with no date set for negotiations.

In a statement on the strike Monday morning, the United Association Plumbers and Steamfitters Local 367 says its action “will affect ENSTAR operations in Anchorage, the Kenai Peninsula, and in the Mat-Su Valley,” but will not affect the utility’s emergency operations.

“Although the strike began at 6 a.m., the union has instructed its emergency dispatchers to remain on duty until management arrives later Monday morning,” union officials wrote. “The union has also instructed emergency crews to stay on the job as long as necessary to safely and professionally secure work sites and equipment before taking part in the strike.”

Union officials say the decision to strike followed a split vote on whether to accept a contract offer from ENSTAR’s management, based in Michigan and Canada.

“In a close vote, the clerical employees accepted ENSTAR’s offer,” union officials wrote. “However, the operational employees strongly and emotionally rejected it.”

In a long list of grievances attached to the statement, union workers say their concerns stem from worries about the company’s pension plan. On a deeper level, however, they also fear aggressive moves by the company to cut pensions soon after promising to leave them untouched for two years -- moves which were delayed after “repeated threats from the union,” but are back on the table again now that the agreement has expired.

“ENSTAR’s proposed pension benefit for new hires gives those employees a significantly lower benefit with a significantly greater investment risk,” union officials wrote. “The current employees voted the offer down because they do not trust ENSTAR’s out-of-state owners. They believe that it will only be a matter of time until ENSTAR circles back and takes their benefits as well.”

ENSTAR spokesperson John Sims was unavailable for comment on the strike Monday, beyond a brief statement emailed to media.

“Our focus continues to be on delivering safe and reliable service to our customers,” ENSTAR officials wrote. “ENSTAR has activated its contingency plan. These plans are in place to ensure there are no disruptions in service. If customers have a natural gas-related concern or emergency, please contact your local ENSTAR office.”

Channel 2's Mallory Peebles contributed information to this story.

This is a developing story. Please check and the Channel 2 newscasts for updates.