Stocks on Wall St held on to most of their gains on Wednesday, after a statement from the Federal Reserve offered a moderately brighter economic outlook.
The Fed flagged risks to growth that appeared to leave open the door for further easing, even as monetary policy was left on hold.
Upbeat job market data and a crisis meeting in Cannes about Greece were other factors.
Private employers in the United States added more jobs than expected last month, while planned layoffs dropped sharply, underscoring the view the economy is on a path of slow growth.
The Dow Jones Index was up 197 points, or 1.7%, at 11,855. The Nasdaq Composite was up 33 points, or 1.2%, at 26439.
In London, the FTSE 100 was up 1.15%, the DAX in Frankfurt was up 2.25% and the CAC-40 in Paris was up 1.38%.
The Australian 200 Index fell 48 points, or 1.1%, to finish at 4185 on Wednesday. The NZX 50 fell 24 points, or 0.7%, to close at 3309.
At 8.25am on Thursday, the New Zealand dollar was trading at 79.02 US cents, 76.35 Australian cents, 49.43 pence, 61.75 yen and 0.5743. The Trade Weighted Index was at 69.21.
Brent crude oil was trading at $110.98 per barrel and gold was trading at $US1728.70 per ounce.