Boeing reported a 52% jump in quarterly profit, helped by higher commercial plane deliveries and one-time tax gains, but investors were spooked by rising costs in its military tanker program.

Boeings shares fell as much as 3% after the company said it took a $272 million charge related to its tanker program and maintained its 2014 cash-flow forecast.

Boeing said the charge reflected additional engineering and system installation costs related to the aerial tanker program, which has already raised concerns over cost overruns.

The company retained its cash-flow outlook at $6.25 billion for the year.

Boeing delivered 181 aircraft in the second quarter. This included 30 Dreamliner jets and 124 narrow-body 737s.

The company's ability to churn out Dreamliner jets is crucial to its financial performance this year as it is relying on commercial jets to offset a weak defense business. While Boeing still loses money on each 787 it builds, it gets closer to breaking even as production increases.

The planemaker delivered its first stretched Dreamliner 787-9 in the quarter.

Boeing and its European rival Airbus Group have been ramping up production to cater to increasing demand from airlines. Boeing is going full throttle and said in January it was producing 10 Dreamliner jets per month.

Boeing's delivery forecast shows it is on track to deliver a record 715 to 725 jetliners this year, having delivered 342 in the first half.

The company's net income rose to $1.65 billion, or $2.24 per share, from $1.09 billion, or $1.41 per share, a year earlier.

It recorded tax benefits of $524 million in the quarter, which included a pre-announced benefit of $116 million.

Revenue rose 1% to $22.05 billion, missing the average analyst estimate for the first time in six quarters.