(Reuters) – Pentagon’s No.1 weapons supplier Lockheed Martin Corp missed analysts’ estimates for quarterly profit on Tuesday, as margins slipped in its aeronautics unit that makes the F-35 stealth fighter jets.

The company also forecast 2019 earnings per share below expectations, sending its shares down nearly 1 percent in early trading.

Lockheed expects full-year profit to range between $19.15 per share and $19.45 per share, below the average analyst estimate of $19.55, according to IBES data from Refinitiv.

Lockheed and other U.S. weapon makers are expected to benefit from higher defense spending when President Donald Trump unveils the fiscal 2020 defense budget alongside stronger global demand for fighter jets and tanks.

The company delivered 91 F-35 jets in 2018, up from 66 jets a year earlier. Lockheed has said it aims to deliver more than 130 F-35s in 2019.

Operating margins at the aeronautics division, its biggest, fell to 10.6 percent in the three months ended Dec. 31, from 11.6 percent a year earlier.

The company earned $4.39 per share from continuing operations, slightly short of estimates of $4.40 per share.

Net sales rose 4.1 percent to $14.41 billion.