SYDNEY (Reuters) - Australian miner Fortescue Metals and three other local blue-chip firms faced the prospect of messy law suits on Friday, with aggrieved investors engaging lawyers in their efforts to recoup or prevent losses.

Fortescue, the country's third-largest iron ore miner, felt the sting of legal action when one of its major investors sued it to prevent it from raising more debt funding, saying this would eat into its own returns as a bondholder.

Fortescue on Friday rejected the move by U.S. bondholder and major shareholder Leucadia National Corp, which argues it is entitled under the terms of a 2006 bond issue to 4 percent of the miner's revenues. Leucadia is worried Fortescue plans to issue more bonds backed by the same portion of revenues.

"Leucadia does not believe that (Fortescue) has the right to issue additional notes which affect Leucadia's interest...," the investor said in a U.S. filing this week.

"Leucadia is outraged that Fortescue and its chief executive officer, Andrew Forrest, now assert this claim."

(Leucadia's filing: http://link.reuters.com/ruh29n)

Investors are also considering legal action against drug company Sigma Pharmaceuticals over a September 2009 capital raising and against farm-industry suppliers Nufarm and Elders after both made profit warnings.

"We have identified a number of common issues between Nufarm and the Elders claims," senior lawyer Ben Phi, of class-action specialists Slater & Gordon, said in a statement on Friday.

In July, Nufarm halved its full-year profit forecast and raised its debt projection, blaming a late, cold winter in North America and Europe for hitting demand. Less than three months earlier, Nufarm had raised A$250 million in a share issue.

Nufarm is one-fifth owned by Sumitomo Chemical.

In June, Elders shares tumbled 44 percent to a record low A$0.46 after a profit warning. It had raised capital in 2009 on the promise of a better second-half.

Sigma said it would vigorously defend any law suit.

An Elders spokesman said: "We believe that our governance procedures were entirely appropriate and we complied with all of our continuous-disclosure requirements."

Nufarm did not return a call seeking comment.

Fortescue shares fell 1.8 percent to A$4.80, underperforming a flat broader market.

The miner said that while it had raised the prospect of issuing further notes, it had not taken any steps to do so and that no damage had been suffered by Leucadia.

(Reporting by Balazs Koranyi, Ed Davies and Amy Pyett; Editing by Mark Bendeich)