PrivateBancorp Inc (PVTB.O) posted a third-quarter loss, as weakness in commercial real estate forced the Chicago lender to almost triple its provision for bad loans, and said it would raise $175 million through a stock offering, sending its shares down 14 percent in pre-market trade.

The company said credit quality continued to decline in the third quarter and warned that non-performing assets could increase for the next several quarters.

In the fourth quarter, the growth in non-performing assets is expected to be meaningful, but at a rate less than the sequential increase in the third quarter, the company said in a statement.

The company said proceeds from the share offering may be used for working capital and deals backed by the Federal Deposit Insurance Corp.

On completion of the offering, the company would be eligible to request the U.S. Treasury to reduce the number of common shares issuable upon exercise of warrants the Treasury held, by 50 percent to 645,013 shares, the company said.

Separately, the company named C. Brant Ahrens as its chief operating officer, replacing John Williams, who would continue as chairman of The PrivateBank Milwaukee.

For the third quarter, PrivateBancorp posted a loss of $31.2 million, or 68 cents a share, available to common shareholders, compared with $7.8 million, or 25 cents a share, a year earlier.

Provision for loan losses almost tripled to $90 million.

Non-performing assets as of Sept. 30 was 396.6 million, or 3.28 percent of total assets, compared with $106.5 million, or 1.18 percent, a year back.

PrivateBancorp provides personalized financial services primarily to entrepreneurial and middle-market companies, affluent individuals, wealthy families, professionals, entrepreneurs and real estate investors.

Operating expenses stemming from its aggressive growth strategy and significant exposure to commercial real estate loans have hurt the company in the past, as it posted five consecutive quarterly losses, before turning profitable in its fiscal first quarter. Shares of the company were down 14 percent to $16.30 in pre-market trade. They closed at $19 Friday on Nasdaq. The shares have more than doubled in value since hitting a 52-week low of $9.08 in March.