(Reuters) - Starboard Value LP, a large shareholder in Smithfield Foods Inc , urged the world's largest pork producer to explore a breakup rather than go ahead with a planned $4.7 billion takeover by Chinese meat company Shuanghui International.

The activist shareholder, which disclosed a 5.7 percent stake in the company on Monday, said Smithfield might be worth "well in excess" of the $34 per share offered by Shuanghui if it split into hog production, pork and international units and shopped the businesses separately.

Starboard said in a letter dated June 17 to Smithfield's board its sum-of-the-parts valuation was between $44 and $55 per share.

Officials from Smithfield and Shuanghui were not immediately available to comment. The Starboard letter was earlier reported by the Wall Street Journal.

Starboard's call for a break-up echoed an earlier one from investor Continental Grain Co, which later dropped its demand after Shuanghui made a deal to buy the hog farmer and pork processor.

The planned purchase by Shuanghui would be the largest by a Chinese company of a U.S. firm to date. (http://link.reuters.com/heq88t)

Shares of Smithfield were up 1.4 percent at $33.25 in trading before the market opened.

(Reporting by Sakthi Prasad and Siddarth Cavale in Bangalore and Martinne Geller in New York; Editing by Edwina Gibbs, Lisa Von Ahn and Jeffrey Benkoe)