The European Central Bank is set to cut its inflation forecasts on Thursday but hold back from concrete policy action, promising only to beef up its bond-buying program if prospects weaken further. The bank is expected to leave interest rates unchanged and argue that the chance of missing its medium-term inflation target has increased due to lower oil prices and weaker growth in China. The ECB launched the 60 billion euro ($67.7 billion) per month quantitative easing program in March to boost consumer prices after a short bout of deflation.