VIENNA—The European Central Bank could raise rates as soon as the end of next year, and calling an end to bond purchases would be a strong signal that the move is coming in the next two quarters, Governing Council member Robert Holzmann said on Wednesday. The ECB last week took another step in rolling back crisis-era stimulus, saying it would end emergency bond purchases in March but temporarily double the pace of its longer-running Asset Purchase Programme (APP) to ease the transition. “We can reduce or suspend the APP purchases that are still outstanding, and if that happens then it is a price signal to the markets because we have established that only after the suspension or cessation of the purchases will interest rates be increased,” Holzmann told a news conference. “In an extreme case it would be possible … to suspend the purchases in a data-driven way this year …