Boeing Co (BA.N) reported a nearly 9 per cent fall in quarterly profit, hurt by an after-tax charge related to the KC-46 aerial refueling tanker it is developing for the U.S. Air Force.

The world's largest plane maker earned $1.22 billion, or $1.83 per share, in the first quarter ended March 31, compared with $1.34 billion, or $1.87 per share, a year earlier.

The company recorded a tanker charge of $156 million or 24 cents per share in the quarter.

Core earnings, which exclude pension and other costs, fell to $1.74 per share from $1.97.

Revenue rose about 2 percent to $22.63 billion.

Commercial aircraft deliveries fell 4.3 percent to 176.