(Reuters) - Boeing ( BA ) shares fell 2.7% in U.S. premarket trading on Thursday after about 33,000 striking workers voted to reject a new labor offer, deepening the crisis at the U.S. planemaker a day after it reported a $6 billion loss.

64% of the votes cast were against the labor agreement, which offered a 35% general wage increase over four years but no defined benefit pension plan, which was one of the workers' main demands.

The rejection means a strike, which has lasted for over five weeks, will continue, further impacting Boeing ( BA ) and its fragile supply chain as they were already reeling from a halt in production of the company's best-selling 737 MAX jets and its 777 and 767 widebodies.

(Reporting by Abhijith Ganapavaram in Bengaluru; Editing by Mrigank Dhaniwala)