Orbital Sciences has received approval from its shareholders to proceed with its planned $5bn merger with Alliant Techsystems’ (ATK) Aerospace and Defense operations.

The transaction is expected to be concluded on 9 February 2015, following which Orbital common stock will be delisted on the New York Stock Exchange.

"The combined company will be called Orbital ATK, which will have Orbital’s small and medium-class satellite and launch vehicle portfolio and ATK’s rocket propulsion, composite structures and space power systems."

Orbital chairman David Thompson said:"We are now on a clear path to completing the merger and beginning operations of Orbital ATK two weeks from today."

ATK and Orbital signed a deal for the transaction in April 2014. Under the deal, each share of Orbital stock will be converted into the right to receive 0.449 shares of common stock of ATK.

The combined company will be called Orbital ATK, which will have Orbital’s small and medium-class satellite and launch vehicle portfolio and ATK’s rocket propulsion, composite structures and space power systems.

The company will offer space launch vehicles, propulsion systems, tactical missiles, defence electronics, satellites, space and armament systems, ammunition, commercial and military aircraft structures, as well as related components for the US and international markets.

Orbital ATK is estimated to generate annual revenues of $4.5bn, with more than $575m in earnings before interest, taxes, depreciation, and amortisation (EBITDA) based on fiscal 2013 results.