ConAgra Foods Inc posted an unexpected dip in quarterly revenue on Thursday as its commercial foods business passed on lower costs for wheat.

The company's shares fell even though profit met expectations. ConAgra's key consumer foods segment showed 3 percent volume growth, helped by sales of products that consumers embraced during the recession, such as Banquet frozen dinners and Chef Boyardee pasta.

In recent years, the company has sold off commodity trading and other operations to focus on product development and marketing of brands like Healthy Choice and Marie Callender's meals.

That investment has helped lift sales in the once moribund consumer foods business, which makes up more than two-thirds of the company's sales.

Sales in that unit rose 2 percent in the quarter.

ConAgra said profit rose to $228.7 million, or 51 cents a share, in the third quarter ended on February 28 from $193.12 million, or 43 cents a share, a year earlier.

Excluding one-time items, earnings were 44 cents a share, matching the analysts' average estimate, according to Thomson Reuters I/B/E/S.

Sales fell 1 percent to $3.10 billion, as the company's flour milling operation passed on lower prices to customers. Analysts on average forecast $3.15 billion.

For the year, ConAgra still expects earnings of $1.73 cents a share, excluding one-time items.

ConAgra shares were down 1.3 percent at $25.75 in trading before the market opened.

(Reporting by Brad Dorfman; Editing by Derek Caney and Lisa Von Ahn)