RESEARCH TRIANGLE PARKTransEnterix is raising $69 million in a stock offering but its shares were hammered, falling more than $1 to a low of $2.57 after the deal was announced late Tuesday night.

Shares were still down more than 13% from Tuesday’s close of $3.61 in midmorning trading Wednesday.

The robotic surgey technology firm announced it had struck a deal with Wall Street firm H.C. Wainwright & Co. to sell more than 23 million shares at $3. An option for an additional 3.46 million shares also was offered.

In a statement, TransEnterix said the stock offering was increased in size “due to demand.”

The deal is expected to close Friday.

“The gross proceeds of the offering are expected to be approximately $69.25 million, prior to deducting underwriting discounts and commissions and estimated offering expenses and excluding the exercise of the underwriter’s option to purchase additional shares,” TransEnterix said.

“The Company intends to use the net proceeds from this offering for general corporate purposes, including working capital and funding research and development activities.”