FORT WORTH, Texas—Bell Helicopter and the union representing 2,500 manufacturing workers remain at an impasse during the fifth week of the strike in Texas.

Both sides ended a long day of negotiations late Wednesday without reaching an agreement.

United Auto Workers Local 218 went on strike in mid-June at several Dallas-Fort Worth area plants. Members had rejected a three-year contract because of proposed increases in medical costs and plans to outsource janitors’ work.

Union officials said Thursday that the company has repeatedly shown its unwillingness to hear their members’ concerns.

But Bell says it’s committed to reaching a mutually agreeable solution that will get everyone back to work and will meet the company’s and employees’ needs.