AtriCure Inc., a Butler County-based maker of medical devices used in heart surgery, announced Wednesday it intends to offer shares of its common stock in a public offering.

The company said it plans to use the net proceeds from the offering for general corporate purposes and working capital.

AtriCure announced the pricing of the public offering of 3,475,000 shares of common stock at a price of $7.25 per share.

AtriCure has also granted the underwriter a 30-day option to purchase up to an additional 521,250 shares of common stock to cover over-allotments, if any. Piper Jaffray & Co. is acting as the sole manager for the offering.

Net proceeds from the sale of the shares are expected to be approximately $23.5 million. The offering is subject to customary closing conditions and is expected to close on Tuesday.

Earlier this month, the company said preliminary revenue for the fourth quarter of 2012 is expected to be approximately $18.4 million, 9.5 percent more than the fourth quarter of 2011. Preliminary revenue for full year 2012 is expected to be $70.2 million, reflecting year-over-year growth of 9.1 percent from 2011.