TCF Financial Corp.'s third-quarter profit jumped 42 percent, shaped by higher revenue and a sharp drop in credit losses.

But the company's stock fell 6 percent amid a broader sell-off Monday as analysts expressed concern about expenses.

The company, which runs Minnesota's third-largest bank by deposits, said it earned $86.2 million in the July-to-September period, up from $60.5 million a year ago.

Revenue was $365.6 million, up 6.5 percent.

TCF reported a 11.5 percent gain in interest income, which accounts for about three-fourths of its revenue.

Noninterest income rose 6.6 percent, helped by credit card fees and a sizable jump in its leasing and equipment finance business. Its provision for credit losses fell more than 80 percent to just over $2 million for the quarter.

TCF's expenses grew at a slower rate than revenue in the latest quarter. Even so, analysts pressed executives for details about their spending expectations in coming months.

TCF is spending more to build services in digital banking and boost its home loan business, executives said.

They noted some expense growth associated with a new operations center in the Twin Cities.

"I think expenses are well controlled where we are in here," Brian Maass, the company's chief financial officer, told analysts. "We are choosing to make a couple of investments in the business, and we think that those will provide us growth in revenue in the future as well."

TCF's tax expense fell 9 percent, chiefly due to the lower federal corporate tax rate set late last year.

The company's net interest margin, the difference between what it charges borrowers and what it pays depositors in interest, was 4.66 percent, up from 4.61 percent a year ago.