Commodities trading risk at JPMorgan Chase & Co rose slightly in the first quarter from the previous three months but slumped from a year earlier as prices of raw materials seesawed.

JPMorgan, the largest U.S. bank, said its value-at-risk (VaR) in commodities stood at $15 million in the first quarter, compared with $14 million in the 2012 fourth quarter and $21 million in the 2012 first quarter.

Commodity prices as indicated by the Thomson Reuters-Jefferies CRB index fell nearly 2 percent in the first quarter, tumbling in January, rebounding in February, then sliding again in March.

JPMorgan, typical of Wall Street banks, groups its commodities revenue under the fixed income category and does not break down the sector individually, often leaving VaR as one of its key risk-reward indicators for commodities.

For the first quarter, JPMorgan said fixed income revenue fell 5 percent from a year earlier to $4.8 billion.

The bank posted a higher first-quarter profit as it recovered from trading losses in the "London Whale" episode that cut into earnings last year.

Most Wall Street banks reported a sharp drop in commodities risk in the fourth quarter due to market uncertainty.

(Reporting by Barani Krishnan; Editing by Lisa Von Ahn and John Wallace)