CHS Inc., the nation's largest farmer-owned cooperative, Wednesday reported sharply lower earnings for its second quarter because of reduced margins in its refined fuel, crop nutrients and grain marketing businesses.

The Inver Grove Heights-based cooperative said earnings for the quarter ended Feb. 29 totaled $78.5 million compared with $194.6 million a year earlier. Revenue rose 14 percent to $8.8 billion.

Margins declined for both the CHS refinery at Laurel, Mont., and the National Cooperative Refinery Association, of which it owns nearly 75 percent. CHS propane and renewable fuels operations reported increased earnings. Energy segment earnings for the first six months are ahead of last year largely because of higher refining margins in the first quarter.

Second-quarter earnings also declined within its agriculture business unit. Lower profit margins in wholesale crop nutrients and grain marketing offset increased margins in retail operations, CHS said.

CHS said margins declined in its financing businesses and its two food-related joint ventures.

For the first six months of fiscal 2012, earnings were up 25 percent to $494.7 million. Revenue totaled $18.6 billion compared with $15.8 billion for the same period last year, reflecting higher values for commodity energy, grain and crop nutrients products.

Susan Feyder • 612-673-1723