The Iowa-based Renewable Energy Group Inc. (REGI) plans to acquire Syntroleum, an Oklahoma-based energy company, pending shareholder approval. Syntroleum is a-50 percent partner with Tyson Foods in a large diesel fuel production plant in Louisiana.

Renewable Energy Group has agreed to buy nearly all of Syntroleum's assets and assume all the material debt as well. The terms call for Syntroleum to receive 3.976 million shares of REGI common stock worth an estimated $42 million, The City Wire reported.

Syntroleum and Tyson jointly own 50 percent in Dynamic Fuels, a 75-million gallon renewable diesel production facility that has been inactive throughout 2013. It is estimated that each partner has lost about $1 million per month the plant has been idle, in addition to the loss of about $20 million in potential sales.

REGI owns and operates eight active biodiesel refineries in four states with a combined production capacity of 257 million gallons. It also distributes biodiesel through a national network.