Syntroleum Corp., which owns half a biofuels plant in Geismar, said unasked-for offers to buy the company, its assets and intellectual property prompted the firm to begin investigating strategic alternatives to increase shareholder value.

Syntroleum announced July 17 it had hired Piper Jaffray & Co. for advice on the best strategy to improve the value of Syntroleum’s shares. At the time, Tulsa, Okla.-based Syntroleum said it would not update the evaluation process.

However, the company said Friday media and investor inquiries prompted the explanation.

Piper Jaffray is now contacting additional companies to gauge their interest in the company. Syntroleum said there can be no assurances about which particular strategic alternative the company will choose.

One of Syntroleum’s major assets is half of the $160 million Dynamic Fuels plant in Geismar. The plant, which makes synthetic fuel from animal fat, has an annual production capacity of 75 million gallons of fuel. But the plant has had production problems. The plant closed in October for a turnaround and was scheduled to reopen in July. However, Syntroleum officials have refused to comment on whether the plant will resume operations.