Shares of Boeing Co. /zigman2/quotes/208579720/composite BA -0.17% slid 1.1% in premarket trading Wednesday, after the aerospace and defense giant swung to a large second-quarter loss on weakness in commercial airplanes, although it was narrower than expected, but did not provide any guidance given the uncertainty of the timing and conditions for the return to service of the 737 Max fleet. The company reported a net loss of $2.94 billion, or $5.21 a share, after a profit of $2.20 billion, or $3.73 a share, in the year-ago period. Excluding non-recurring items, the adjusted per-share loss was $5.82, compared with the FactSet consensus for a loss of $6.69 a share. Revenue dropped 35% to $15.75 billion, but topped the FactSet consensus of $15.05 billion. Commercial airplane revenue tumbled 66% to $4.72 billion, below the FactSet consensus of $6.61 billion, as deliveries fell 54% to 90 planes and the segment swung to a loss of $4.95 billion from a profit of $1.79 billion. Defense, space and security revenue rose 8% to $6.6 billion to beat expectations of $6.51 billion. "This is a defining moment for Boeing and we remain focused on our enduring values of safety, quality, and integrity in all that we do, as we work to safely return the 737 MAX to service," said Chief Executive Dennis Muilenburg. The stock has lost 0.6% over the past three months through Tuesday, while the Dow Jones Industrial Average /zigman2/quotes/210598065/realtime DJIA +0.40% has gained 2.8%.