By Katy Burne Of DOW JONES NEWSWIRES NEW YORK -(Dow Jones)- TTX Co., a U.S. railcar and freight services provider, is preparing to sell $150 million in 30-year debt that is expected to price late Thursday, according to a person familiar with the sale. The bonds are expected to be rated Baa1 by Moody's Investors Service and A+ by Standard & Poor's. Citigroup Inc. (C) and Credit Suisse Group (CS, CSGN.VX) are leading the sale, with proceeds expected to be used for general corporate purposes including repayment of short-term debt and for equipment purchases. Price talk on the bonds is not yet out. -By Katy Burne, Dow Jones Newswires; 212-416-2213; Katy.Burne@dowjones.com.