NEW YORK, July 10 (Reuters) - U.S. Treasury debt prices retested their session highs midmorning on Friday after a survey showed a steeper-than-expected deterioration in consumer confidence in early July.

Reuters and the University of Michigan said their survey's overall index of consumer sentiment in early July declined to 64.6, falling short of analysts' forecast of 70.5. It finished at 70.8 in June. For more, see [ID:nNYS005222]

Economists monitor this barometer as a proxy of future consumer spending, which makes up about 70 percent of the U.S. economy.

The price on benchmark 10-year Treasury notes US10YT=RR was up 20/32, compared with 19/32 higher shortly before the release of the Reuters/University of Michigan consumer survey.

Their yield, which moves inversely to the price, was 3.33 percent versus 3.34 percent prior to the survey. It ended at 3.41 percent on Thursday. (Reporting by Richard Leong, Editing by Chizu Nomiyama)