Boeing Co.’s stock slid 2.8% Wednesday, after the company said it has reached an impasse in its talks with its machinists union to end a strike that estimates say is costing it more than $1 billion a month.

Boeing withdrew a contract offer for 33,000 machinists who have been on strike since mid-September, and said further negotiations “do not make sense at this point.”

Boeing and the union that represents 33,000 striking employees at the company say talks between the two have broken down and no new talks are scheduled.

Negotiations between airplane maker Boeing and its union broke down this week with both sides pointing the finger at the other for their current standoff with a strike that is approaching one month.

Boeing has withdrawn a contract offer that would have given striking workers 30% raises over four years after talks broke down.

Boeing has withdrawn its contract offer two days after returning to negotiations. The IAM said the planemaker was "hell-bent" on its second offer.

Boeing made an improved offer last month that was described as its "best and final," but union members say that wasn't enough.

Boeing on Tuesday said that it has withdrawn its pay offer after negotiations with the International Association of Machinists and Aerospace Workers (IAM), whose members are on a strike against the company.

Talks between Boeing Co. and its largest union to end a strike have collapsed for a third time, extending a shutdown to the planemaker’s key commercial manufacturing base on the US west coast.

Boeing said on Tuesday that it had withdrawn its pay offer to around 33,000 U.S. factory workers and no further negotiations were planned with their union representatives as a financially damaging strike nears its fourth week.