TREASURIES-U.S. Treasury yields trim rise after 30-year auction

NEW YORK, Sept 13 (Reuters) - U.S. Treasury yields retreated from their session highs on Wednesday in the wake of mediocre demand at a $12 billion auction of 30-year bonds, the final part of this week's $56 billion in coupon-bearing government supply.

At 1:20 p.m. (1720 GMT), the yield on 30-year Treasury bonds on the open market was 2.779 percent, up 0.4 basis point from late on Tuesday, Reuters data showed. (Reporting by Richard Leong; editing by Diane Craft)