Nashville barge operator Ingram Barge Co. is suing a former customer for $4.6 million over a contract dispute linked to a now-shuttered West Virginia smelting facility.

Ingram Barge filed suit Tuesday in federal court against Century Aluminum of West Virginia, stating that the company has failed to meet two separate agreements. Ingram was to ship both alumina and calcined coke from Century's smelter in Ravenswood, W. Va., but the metal producer failed to provide tonnage it had agreed to, according to the suit.

Dan Mecklenborg, senior vice president and chief legal officer for Ingram, said the amount is significant and worth recouping, but that the loss would not place the company in jeopardy.

"I would say that it's very rare for Ingram to initiate legal action against one of our customers," he said.

The lawsuit cites two agreements reached in 2006, one for the annual shipping of 360,000 tons of alumina from 2007 through 2010. A separate agreement calls for 77,000 tons of coke shipped annually from 2008 through 2010, according to the suit. Ingram states that in 2009 Century shipped more than 41,000 tons of aluminium, far shy of its commitment, and no coke at all.

The West Virginia company is part of Century Aluminum Co. of Monterey, Calif., a publicly traded enterprise that showed a nearly $182 million loss through the third quarter of 2009. The company turned a profit of more than $40 million in the third quarter alone, but has been running at an annual loss since 2005, according to filings with the U.S. Securities and Exchange Commission.

And according to its SEC filing, Century ended operation of its Ravenswood plant, the site of its shipping agreement with Ingram, by early 2009.

"The decision to curtail operations was due to the relatively high operating cost at Ravenswood and the depressed global price for primary aluminium," the company reported to the SEC.

Michael Dildine, Century's media contact, stated by e-mail that the company does not comment on litigation.

The companies are currently scheduled for a case management conference March 29.