Xcel Energy to offer 15 million shares of stock

Utility Xcel Energy said it began an offering of 15 million shares of common stock, worth about $312.9 million at the stock's Tuesday closing price of $20.86.

Underwriters have an option over the next 30 days to buy up to 2.25 million additional shares to cover overallotments.

Morgan Stanley and Citigroup are acting as joint bookrunning managers for the offering. The company expects to close the sale of the shares on Monday.

Net proceeds are expected to be added to general funds and repay commercial paper, the company said.

Shares fell 83 cents, or 4 percent, to $20.03 during aftermarket electronic trading.