Jan 18 (Reuters) - U.S. stock index futures briefly extended gains on Wednesday as retail sales fell more than expected in December, fueling hopes of smaller rate hikes from the Federal Reserve.

Another report showed U.S. producer prices rose less than expected year-on-year in December, adding to evidence of a moderation in inflation.

At 8:32 a.m. ET, Dow e-minis were up 72 points, or 0.21%, S&P 500 e-minis were up 17 points, or 0.42%, and Nasdaq 100 e-minis were up 75.5 points, or 0.65%.

Moments before the data, Dow e-minis were up 38 points, or 0.11%, S&P 500 e-minis were up 10.25 points, or 0.26%, and Nasdaq 100 e-minis were up 43.25 points, or 0.37%. (Reporting by Amruta Khandekar; Editing by Shounak Dasgupta)