Nearly 3,600 Sikorsky Aircraft workers in Connecticut and Florida went on strike Monday, blaming increased health insurance costs in the company's contract offer.

Workers with Local 1150 of the Teamsters overwhelmingly rejected the contract and voted Sunday in favor of the strike, the company's first since 1963. The union represents 3,500 workers at the helicopter-maker in Connecticut and 90 in Florida.

Union members began picketing early Monday morning at the company's Stratford headquarters and locations in West Haven, Bridgeport, Shelton and West Palm Beach, Fla. The most recent contract expired at midnight Sunday.

Sikorsky officials countered that they believed the contract was a good offer, considering that it also included 3.5 percent pay raises in each year of the three-year deal, pension improvements and a $2,000 ratification bonus.

"We are disappointed that union members failed to ratify the contract," Elizabeth Amato, Sikorsky's vice president of human resources, said in a statement Sunday. "The company presented what we believe is a fair and equitable contract that is competitive with the region and the industry."

No incidents were reported. However, traffic heading into the Stratford facility was backed up onto the Merritt Parkway, WICC of Bridgeport reported.

"There are plenty of people inside Sikorsky to make our aircraft," Sikorsky Vice President Bud Greeby told WICC. "Many of these are former line workers who are supervisors."

No new contract talks were scheduled.

Negotiators for Local 1150 did not recommend that members ratify the agreement, which workers turned down by a vote of 2,045 to 1,072 Sunday.

Negotiators and the union's secretary treasurer, Rocco Calo, cited a doubling of health care co-payments in the first year and a 15 percent increase over the next two years, according to the Web site.

The proposed contract also would have raised prescription costs and doctor visit copays, "among other costly increases."

"What people made the decision on was the medical package," Calo said after Sunday's vote. He added that workers would remain on strike "as long as it takes."

Workers rallied outside the voting place Sunday.

"We're tired," said Fred Nowling, a union worker from West Haven, in comments about company officials. "They kept shoving and shoving and shoving and we're tired of it now."

Sikorsky, a unit of United Technologies Corp. (UTX), employs about 9,500 workers in Connecticut, including about 3,500 Teamsters and 6,000 salaried workers. The company makes civilian and military helicopters, including S-76 executive transport models, Army Black Hawks and Navy Seahawks.

Union members had been preparing for the possibility of a strike by forming a 100-member strike committee to make plans for picket lines, emergency financial assistance and other potential necessities.