Helix Energy Solutions Group has completed its combination with Hornbeck Offshore Services after shareholders approved the all-stock transaction, creating a larger U.S. offshore services group under the Hornbeck name.

Helix shareholders approved the proposals needed to complete the deal at a special meeting, and the merger became effective on September 1.

The transaction effectively ends the Helix corporate name. The combined company will operate as Hornbeck Offshore Services and will trade on the New York Stock Exchange.

Hornbeck securityholders will own about 55% of the combined company on a fully diluted basis, while former Helix shareholders will retain roughly 45%. Todd Hornbeck will serve as president and chief executive, and William Transier will chair the seven-member board.

Under the original merger terms, Hornbeck shareholders will receive 10.27167 Helix shares for each Hornbeck share they hold. The companies agreed to the transaction in April, with Hornbeck investors including Ares Management funds supporting the combination from the outset.

As Splash reported when the deal was announced, the merger combines Helix’s well intervention, subsea robotics and trenching businesses with Hornbeck’s high-specification offshore support vessel fleet. The companies are targeting deepwater oil and gas, defence and offshore renewables work.

The combination is expected to generate at least $75 million in annual revenue and cost synergies within three years. Management has said one of the main benefits will be reduced reliance on third-party vessel charters, along with savings in maintenance, procurement and operations. For customers and competitors, the deal also brings together services and vessel capacity that have historically sat in separate parts of the offshore supply chain.

The merger comes after Helix removed its U.S. shallow-water abandonment business from the portfolio. The company sold Helix Alliance to the Chouest Group for $107.5 million in May, leaving it more focused on deepwater well intervention, robotics and subsea services ahead of the Hornbeck transaction.

Hornbeck adds a sizeable Jones Act and high-spec OSV platform focused on the Gulf of America and Latin America, as well as U.S. government and emerging non-oilfield work. Splash recently reported that the company was also investing in nuclear technology startup Deployable Energy to explore maritime uses for transportable microreactors.