TREASURIES-Longer-dated price turn flat after Fed buy

NEW YORK Nov 30 (Reuters) - Prices on longer-dated U.S. Treasuries prices turned flat on Friday, paring earlier gains after the Federal Reserve completed its latest purchase of federal debt for its "Operation Twist" program.

The U.S. central bank b ought $1. 8 5 billion in Treasuries that mature in Feb. 2036 to Nov. 2042.

Operation Twist , due to expire at year-end , was intended to lower l ong-term i nterest rates in an effort to support the economy.

Benchmark 10-year Treasury notes were unchanged on the day, retreating from an earlier gain of 7/32. The 10-year yield was 1.616 percent, little changed from la te on Thursday.