The private equity owner of St. Charles-based American Railcar Industries has agreed to sell the railcar company's manufacturing business to The Greenbrier Cos. Inc. (NYSE: GBX) in a deal valued at about $400 million. ITE Rail Fund, which is managed by ITE Management LP, took American Railcar Industries (ARI) private in a $1.75 billion deal that closed in December. ITE Management has agreed to sell certain assets of ARI's manufacturing business for $430 million, before an adjustment for $30 million...