By Robert Wall

LONDON--The strong dollar is making the leasing of planes more difficult for some airlines outside the U.S. though overall demand for rented jets remains good, the chief executive of Irish leasing company Avolon Holdings Ltd. (AVOL) said Wednesday.

"In the emerging world there are pockets where there are some challenges driven less by demand but more by dollar strengthening," Domhnal Slattery said in an interview. Low oil prices, which ease cost pressures on airlines, are helping to mitigate the currency effect, he said.

Avolon on Wednesday announced a 36% rise in first-quarter net income to $49 million on a 30% rise in sales in the three months to March 31. The company has already found operators for all new planes it is due to receive this year and next, Dublin-based Avolon said.

Key markets are healthy with U.S. carriers posting strong results, Mr. Slattery said, adding that "we are actually seeing the European airlines for the first time in many, many years looking a bit more positive."

Russia, where a plunging ruble and economic weakness hit demand last year, also appears to be stabilizing, said John Higgins, the company's chief commercial officer. "We see the potential for some recovery in the market," he said. Avolon has leased planes to Aeroflot (AFLT.MZ), Russia's largest carrier.

A decision by Airbus Group N.V. (AIR.FR) to cut planned production of the A330 widebody should help sustain pricing for leases of such planes, which has shown some weakness, Mr. Slattery said. Airbus said this year it would cut output of A330s to six planes a month from 10 in 2016.

Write to Robert Wall at robert.wall@wsj.com

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