June 25 (Reuters) - U.S. stock index futures extended gains on Thursday as a largely in-line inflation reading fueled hopes for a less hawkish Federal Reserve.

A Commerce Department report showed the Personal Consumption Expenditures (PCE) Price index rose 0.4% in May, compared with a 0.5% increase expected by economists polled by Reuters. Annually, it stood at 4.1% in-line with estimates.

The core reading increased 0.3% on a monthly basis, in line with estimates. It stood at 3.4% on a year-on-year basis.

At 8:34 a.m. ET, Dow E-minis YMcv1 were up 133 points, or 0.25%, and S&P 500 E-minis EScv1 were up 59.5 points, or 0.8%. Nasdaq 100 E-minis NQcv1 were up 679 points, or 2.3%.