In the wealth management arm, falling stock markets and gyrating currencies reduced customer balances, resulting in lower fees. Fees also dropped from fewer new transactions in the quarter.

But wealth clients channeled $17.1 billion in net new fee generating assets to the bank, after almost no net inflows in the second quarter.

UBS said it would continue a program to buy back shares for around $5.5 billion this year.

UBS is one of the world’s largest wealth managers by assets and in terms of its international scale. It serves the global rich with banking and wealth management and competes in some areas on Wall Street.

The bank is regarded as more stable than many European peers because much of its lending is in conservative Switzerland or to the very wealthy—and because it scaled back its investment bank after the global financial crisis. UBS’s relative stability contrasts with the turmoil at its main domestic rival,

Credit Suisse Group AG

, which is due to give a restructuring update on Thursday.

UBS has been expanding in the U.S. to also serve the not-as-rich. It was going to pay $1.4 billion to buy digital adviser Wealthfront and tap into its technology, but it abandoned the deal in September without giving a reason.

A bright spot for UBS in the quarter was net interest income, which grew on rising interest rates. Banks can make more money when rates are rising, because the gap grows between what they pay for deposits and the interest that they can earn on new loans.

UBS said net interest income rose 14% in its wealth management and personal and corporate banking businesses.

Write to Margot Patrick at margot.patrick@wsj.com