The US aviation giant projected a loss of $5.46 per share, much above the $1.55 foreseen by analysts, according to a profit warning that cited the costs of a new labor agreement, among other factors.

Boeing shares are falling in premarket trading after the plane maker projected a far wider-than-expected fourth-quarter loss following a nearly two-month strike that crippled production.

Shares of Boeing Co (BA) fell nearly 1.5% in Friday’s pre-market session after the planemaker said it expects a GAAP loss per share of $5.46 in the fourth quarter (Q4) which translates to over $4 billion in losses.