Corning's shares slid on Monday after the company unveiled plans for the sale of up to $2 billion of its common stock through an at-the-market equity program.

Shares were down 12% to $145.69 in late morning trading. Despite that decline the stock is up 66% this year.

The materials science and advanced manufacturing technology company said late Friday it entered into an equity distribution agreement to sell the shares from time to time.

As part of the agreement, Corning will set the parameters for the sale of the shares, including price and size limits, among other conditions.

Corning plans to use the proceeds for general corporate purposes, it said.