Rentech Inc. on Thursday reported a smaller fiscal first-quarter loss as the biofuels developer benefited from a rebound in fertilizer prices, an auxiliary business. However, results fell short of analysts expectations.

The Los Angeles company reported a net loss of $5.5 million (3 cents per share) compared with a net loss of $15.5 million (7 cents) a year earlier. Revenue jumped 55 percent to nearly $42.1 million.

Analysts surveyed by Thomson Reuters on average expected the company to report a per-share loss of 1 cent on revenue of more than $45.3 million.

As Rentech continues to develop its crop-based clean fuels business, its wholly-owned subsidiary, Rentech Energy Midwest Corp. provides revenue by selling nitrogen fertilizer. Strong crop economics have fostered a significantly improved environment for fertilizer demand and prices compared to the prior year, the company said.

“Our exceptionally strong fiscal first quarter results reflect the significant rebound in the fertilizer and agriculture markets,” Chief Executive Hunt Ramsbottom said. “We expect a continued positive environment for (Rentech Energy’s) products which supports a robust outlook for the business.”

Rentech continues to project that Rentech Energy’s operating income for fiscal year 2011 will be at least $50 million and earnings before interest, taxes, depreciation and amortization for the fiscal year will be at least $60 million. Construction of its ClearFuels biomass gasifier is on schedule, and production of renewable synthetic jet and diesel fuels is on track by the end of the calendar year.

Shares were down 2 cents, or 2 percent, to $1.31 in midday trading on the New York Alternet.