Los Angeles-based Rentech Nitrogen Partners LP filed with the Securities and Exchange Commission to sell 15 million common units at an anticipated price of $19 to $21 per unit. Post-offering the parent, Rentech, which makes systems that convert biomass to gases, would own about 60.8% of the nitrogen unit's common units.

Morgan Stanley and Credit Suisse Securities (USA) LLC are acting as joint bookrunning managers for the IPO, with Citigroup Global Markets Inc., RBC Capital Markets LLC, Imperial Capital LLC, Brean Murray, Carret & Co. LLC, Dahlman Rose & Co. LLC and Chardan Capital Markets LLC acting as co-managers.

Anthony J. Richmond, Brett E. Braden and David A. Zaheer of Latham & Watkins LLP are representing the company, with G. Michael O'Leary of Andrews Kurth LLP serving as underwriter counsel.

The business to be spun out was formed in July 2011 to house Rentech's nitrogen fertilizer assets. It owns a facility in East Dubuque, Ill., capable of producing 830 tons of ammonia per day, the raw material of nitrogen fertilizers popular in the U.S. corn belt.

The unit earned net income of $21.6 million on sales of $141.3 million in the nine months ending June 30, 2011, up from $2.8 million of net income on sales of $96.3 million during the same period ending June 30, 2010. Rentech Nitrogen sees opportunities for organic growth, through a recently launched project to increase ammonia production at its existing facility, as well as through acquisitions. The company in its filing said the nitrogen fertilizer business has experienced significant consolidation in recent years, with the top five domestic producers going from 56% of total capacity in 1999 to 84% in 2010.

"We expect industry consolidation to continue and intend to pursue value-enhancing acquisition opportunities as they arise," the company said in its filing. "We believe that there are nitrogen fertilizer facilities in the United States that could be attractive acquisition targets for us, but whose operations are too small to attract attention from many of our larger competitors."