SEATTLE (REUTERS) - Delta Air Lines aims to hire more than 1,000 pilots by next summer, according to a company memo reviewed by Reuters on Monday (June 21), highlighting an uneven rebound in air travel as the industry works to emerge from the coronavirus pandemic.

The major American carrier also expects United States leisure travel volume this month to return to pre-pandemic levels and is seeing more business travellers return to the skies, chief of operations John Laughter wrote to operations employees.

After heavy losses last year, Delta has said it expects to generate a pre-tax profit in the second half of this one, with a reopening of corporate America by Labour Day in early September.

"The fact that we expect to record a profit in June - just 15 months after the sharpest decline in aviation history - is remarkable," Mr Laughter said in his employee note.

He sounded a note of caution on the timing for building back its international network, however, but cited "welcome openings in markets like Spain, France, Italy and Greece".

The carrier anticipates travel restrictions easing across the Atlantic in the second half of this year, Mr Laughter added.

A spokesman said United Airlines aims to start adding some 300 new pilot hires in the coming weeks, but hiring beyond that would depend "to some degree on the speed at which we recover from the pandemic".

United more broadly aims to hire some 10,000 pilots by 2030, he added.