* Q1 net profit S$1.88 bln vs S$1.74 bln estimate

* ROE 14.7% vs 10.6% a year earlier

* Net interest margin 2.30% vs 1.55% year earlier

SINGAPORE, May 10 (Reuters) - Singapore's second-biggest lender Oversea-Chinese Banking Corp (OCBC) joined bigger rival DBS Group in flagging a peak in interest rates after reporting record quarterly profit on Wednesday thanks to higher net interest margins.

OCBC Group Chief Executive Officer Helen Wong said the bank believed interest rates had peaked and "will go stable".

"We're looking at assumption that we do not see interest rate reduction the rest of the year," she told reporters.

OCBC's January-March net profit rose 39% to S$1.88 billion ($1.4 billion), beating the mean estimate of S$1.74 billion from five analysts polled by Refinitiv.

Its total net interest margin, a key gauge of profitability, rose to 2.30% in the first quarter from 1.55% in the same period a year earlier, but was down from 2.31% in the fourth quarter.

OCBC, Southeast Asia's second-biggest bank by assets, forecast full-year net interest margin would edge up to 2.2% from a previous guidance of 2.1%.

Singapore's banks have been benefiting from strong inflows from wealthy customers amid global economic uncertainty because of the city-state's status as financial safe haven.

OCBC's earnings performance follows those of its peers, with DBS reporting last week a 43% jump in first-quarter net profit that was also a record. Smaller United Overseas Bank posted last month a 74% surge in core net profit.

OCBC's shares rose 0.7% on Wednesday in a flat broader market.

Jefferies Research said OCBC's revised net interest margin guidance was broadly in line with expectations and the broker expected "relatively muted share price reaction".

WEALTH MANAGEMENT

"Our loan portfolio was resilient and our wealth management business continued to attract net new money inflows," OCBC Group Chief Executive Officer Helen Wong said in a statement.

The lender said it was starting to see growth in cross border flows after China's reopening, but it was also closely monitoring volatility in developed markets and geopolitical tensions.

"Looking ahead, we are watchful of tighter financial conditions which may slow global economic growth and elevate overall risks," Wong said.

OCBC, which counts Singapore, greater China and Malaysia among its key markets, said net interest income rose 56% to S$2.34 billion in the first quarter from a year earlier.

Return on equity rose to 14.7% in the first quarter from 10.6% in the same period of 2022.

Meanwhile, Wong said OCBC's clients' exposure to Additional Tier 1 (AT1) bonds of Credit Suisse was "very insignificant".

Investors have been rocked by a Swiss authorities' decision to wipe out $17 billion of Credit Suisse's AT1 debt under its takeover by UBS Group, in a move that hit AT1 holders harder than shareholders.

($1 = 1.3245 Singapore dollars) (Reporting by Yantoultra Ngui; Editing by Jamie Freed and Stephen Coates)