Boeing and the Machinists union will return to the bargaining table Monday, resuming negotiations as the strike enters its fourth week.

Boeing and its largest union will resume contract talks on Friday in a bid to end a strike that has throttled plane production and hammered the finances of the aerospace giant, the union and company said on Wednesday.

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

Boeing and its new management team have not matched the union demands, causing a pause in production at its factories and a huge cash burn that is draining the company's finances. Here's why this strike is a bad sign for Boeing's business and puts more strain on an already stretched balance sheet.

Boeing's and its largest union said on Friday that contract talks will resume on Oct. 7, as both sides seek an agreement to end a strike by around 33,000 of the planemaker's U.S. West Coast factory workers.