A major investor in Smithfield Foods has called on the US meat giant's board to consider splitting the company in three.

Agribusiness Continental Grain, which owns around 6% of Smithfield, has claimed dividing the company would "unlock significant value" for shareholders. It argued Smithfield's share price had fared poorly compared to rivals Tyson Foods and Hormel Foods.

Continental Grain said Smithfield could be split into a hog processor, a company supplying fresh pork and packaged meats and a business focused on its operations outside the US.

"It's time for Smithfield to get serious about creating shareholder value," Continental Grain wrote in a letter to the Smithfield board. "This is an exciting time in the world of food and agribusiness. There are very many positive trends and opportunities in the fields in which Smithfield operates. The three pieces of New Smithfield can achieve excellence and high returns in each of their focused market segments."

Smithfield's hog business has booked a loss of US$74m in the first nine months of the company's current fiscal year. Continental Grain said Smithfield's hog business was a "major drag" on the company's share price despite using "very significant amounts" of the group's capital.

The investor, meanwhile, said returns on Smithfield's investment in its international business were "disappointing". It called on a strategic review of the operations and said Smithfield should consider a sale, a merger led by an agribusiness in Europe or a spin off.

Smithfield is a shareholder in Spain-based packaged meats firm Campofrio. Continental Grain said Smithfield's ownership of what it termed "new Campofrio" could be spun off to shareholders. It added: "We believe there is value in hog production and international but not as part of Smithfield's current configuration."

Smithfield has been looking to focus more of its efforts on packaged meats and Continental Grain said the company's US processing and packaged meats businesses could be a "uniquely valuable piece of Smithfield".

It wrote: "If run by experienced packaged food and consumer product executives, it can be a very exciting company with good growth potential and a very attractive earnings multiple. Companies such as Hillshire Brands and Hormel Foods are real-time examples of that valuation potential."

Continental Grain, which has been a shareholder in Smithfield for almost seven years, said Smithfield's management had had enough time to "provide real results to shareholders".