NEW YORK — Unable to structure a competitive bid for the assets of Smithfield Foods, Inc., Starboard Value L.P. said in a filing with the U.S. Securities and Exchange Commission on Sept. 20 it would vote in favor of Smithfield’s acquisition by Shuanghui International Holdings.

“While we are confident the issuer could have received value in excess of that available pursuant to the proposed merger, we are not able to offer shareholders an alternative proposal at this time,” Starboard said in the S.E.C. filing. “Therefore, at this time, unless another proposal emerges, we plan on voting in favor of the proposed merger.”

In the filing, Starboard said restrictions imposed by the merger agreement between Shuanghui and Smithfield Foods impeded its ability to structure a competitive bid. Most notably, Starboard said the requirement to structure a cash bid from a single entity proved challenging for a bidding group to formalize an alternative proposal prior to the special Smithfield Foods shareholders meeting scheduled for Sept. 24.

Starboard owns approximately 5.7% of Smithfield Foods’ stock and said in a Sept. 3 letter to Smithfield shareholders it was working with interested buyers to construct a bid superior to that offered by Shuanghui. At the time, Jeffrey C. Smith, the managing member of Starboard, said his firm would vote against the proposed merger agreement.

On May 29, Shuanghui entered into an agreement to acquire Smithfield Foods for approximately $7.1 billion, $34 per share, and assumption of debt. On June 17, Starboard Value said the Shuanghui offer undervalued Smithfield Foods and that it estimated the value of the company to be in the range of $43.85 to $55.21 per share if the company is broken up.