U.S. President Joe Biden has proposed a flat defense budget for 2022, despite calls from progressive Democrats to cut Pentagon spending, removing a potential hurdle to profits at defense companies, including Northrop.

"Our team booked competitive new awards and generated higher sales, earnings and cash," Chief Executive Officer Kathy Warden said in a statement.

Northrop said it now expects full-year adjusted earnings per share between $24 and $24.50, up from its prior range of $23.15 to $23.65, and above analysts' average estimate of $23.65, according to IBES data from Refinitiv.

The company raised it 2021 sales outlook to between $35.3 billion and $35.7 billion from $35.1 billion to $35.5 billion.

Sales in Northrop's aeronautics systems unit, which makes the center fuselage for the F-35 jets, rose 5% to $2.99 billion, while operating income increased 17% to $308 million in the first quarter ended March 31.

Higher demand in the F-35 program and E-2 early warning aircraft boosted sales in the unit, the company said.

Sales in Northrop's space systems business jumped 29% to $2.52 billion and operating income surged 37% to $276 million, aided by the production ramp up of its GBSD intercontinental ballistic missiles and higher demand for Next Gen OPIR missile-warning radars.

Excluding the sale of its IT services business, Northrop earned $6.57 per share in the quarter, up from $5.15 per share, a year earlier, topping analysts' average estimate of $5.48 per share.

Total sales rose 6% to $9.16 billion, beating Wall Street's estimate of $8.53 billion.

(Reporting by Mike Stone in Washington and Ankit Ajmera in Bengaluru; Editing by Vinay Dwivedi)

By Mike Stone