Smithfield Foods Inc said an independent proxy advisory firm recommended that shareholders vote for the pork producer's $4.7 billion sale to China's Shuanghui International Holdings Ltd, citing the high offer price.

Institutional Shareholder Services (ISS) said the likelihood of the deal going through has improved after Shuanghui secured financing and received approvals from regulatory and foreign investment authorities.

Shuanghui's planned acquisition of Smithfield at $34 per share would be the biggest purchase in the United States by a Chinese company.

Smithfield shares were trading at $34.16 on the New York Stock Exchange on Thursday morning, suggesting that some investors expect a higher bid.

Activist hedge fund Starboard Value LP, which holds a 5.7 percent stake in Smithfield, said in a letter to the company's shareholders last week that it had received non-binding written indications of interest from other parties willing to pay substantially more than Shuanghui's offer.

The New York-based fund said it planned to vote against the merger to buy more time to get a higher bid finalized.

A special meeting of Smithfield shareholders to vote on the deal will be held on September 24.

(Reporting By Maria Ajit Thomas in Bangalore; Editing by Kirti Pandey)