April 30 (Reuters) - Swiss bank UBS UBSG.S on Wednesday posted better than expected first-quarter net profit, helped by stronger earnings in trading driven by market turbulence in the wake of U.S. tariff turmoil, which it said could delay corporate deals.

Switzerland's biggest bank reported net profit attributable to shareholders of $1.7 billion in the first quarter of 2025, down from $1.8 billion a year earlier, but beating an average estimate of $1.3 billion in a company-provided poll of analysts.

In its investment banking division, global markets enjoyed a record quarter with revenues up 32% year-on-year, underpinned by higher client activity in equities and foreign exchange, UBS said.

The outlook was more muted, however, as the backdrop of sweeping U.S. tariffs raised uncertainty. "The prospect of higher tariffs on global trade presents a material risk to global growth and inflation, clouding the interest rate outlook," UBS said.

UBS expected net interest income in its global wealth management business to decline sequentially by a low-single-digit percentage in the second quarter of 2025 and anticipated a similar decline in its Swiss business.

Continued market uncertainty could delay corporate deals, the bank added.