A sharpening slide in the US dollar unnerved global markets on Friday as investors sought to protect themselves from the possibility of sustained dollar weakness.

As US markets were closing on Friday , the euro stood at a 19-month high of $1.309, up 1.2 per cent, while sterling gained 0.9 per cent to a 1½-year peak of $1.9333. The yen climbed 0.5 per cent to ¥115.66.