(Reuters) - Bank of America Corp BAC.N lowered its annual net interest income guidance on Wednesday to reflect a weakened interest rate environment as the second-largest U.S. lender reported higher-than expected earnings fueled by strong consumer trends.

FILE PHOTO: A Bank of America building is seen in Los Angeles, California, U.S., May 6, 2019. REUTERS/Lucy Nicholson

Rate trends have prompted the bank to scale back its expected full-year net interest margin, a key measure of profitability, to 2% from 3%, executives said on a conference call with analysts.

Net interest income, the difference between interest earned from lending and how much the bank pays for deposits, rose 6% last year.

Its interest margin fell in the second quarter to 2.44% from 2.51% three months earlier, though it was still higher than a year earlier.

Chief Financial Officer Paul Donofrio said on a call with reporters the sequential decline was due to lower long-term interest rates.

“When long-term interest rates fall, we see more people pay off their mortgages and that translates into more mortgage-backed securities being redeemed and that forces us to write off some premiums,” he said. “I don’t think you can extrapolate that into the future because long-term rates have stabilized at this point.”

The lender is the most sensitive of the big U.S. banks to interest rate changes because of its large deposit stock and rate-sensitive mortgage securities.

Consumer banking has held up for the big Wall Street banks that have reported second-quarter results this week, cushioning a blow from weakness in trading and advisory businesses.

But warning signs also emerged with JPMorgan JPM.N, Citigroup C.N and Well Fargo reporting a dip in margins, stoking fears that interest rate cuts could further pressure profit by narrowing the spread between what banks charge on loans and pay on deposits.

In the absence of higher interest rates to help pad revenue, banks can improve margins by reducing expenses.

Chief Executive Brian Moynihan said on call with analysts that 2019 expenses are projected to be lower than 2018, against previous expectations for the bank to have flat expenses through 2020.

Expenses during the quarter were up slightly as the bank invested more in its consumer, commercial and wealth management businesses.

Total loans in its consumer banking unit rose 6%, while deposits were up 3%, pushing income from the business up 13% to $3.3 billion.

“We see solid consumer activity across the board, with spending by Bank of America consumers up 5% this quarter over the second quarter of last year,” Chief Executive Brian Moynihan said in a statement.

Growth in the consumer business helped offset softness in market revenue and Wall Street businesses.

The retail bank and wealth management segments each recorded double digit profit gains while its commercial and markets businesses each saw profit and revenue decline from lower investment banking and trading fees.

Adjusted revenue from Bank of America’s global market business, which includes bond and equities trading, fell 5.7% to $4.18 billion.

Net income applicable to common shareholders rose 10% to $7.11 billion, or 74 cents per share, in the second quarter ended June 30. Excluding items, the bank earned 75 cents per share.

Revenue, net of interest expense, was up about 2% at $23.08 billion.

Analysts had expected a profit of 71 cents per share on revenue of $23.2 billion, according to IBES data from Refinitiv.