DUBLIN—Concerns in the financial community about doing deals in Iran are hampering Airbus Group SE’s ability to close a multibillion-dollar aircraft pact with Tehran, the European plane maker’s head of sales said Wednesday.

“We have to find ways to get money out of Iran through the banking system,” said John Leahy, Airbus chief operating officer for customers. While progress has been made, it has been slower than expected, Mr. Leahy said.

...