The Toronto Stock Exchange followed the lead of other world markets Wednesday, running out to a triple-digit gain after the world's central banks pledged to work together to fight Europe's slumping economy.

The S&P/TSX Composite Index closed higher by 471.67 points, or four per cent, to 12,204.17. That's the first time the TSX has been above the 12,000 level since November 16.

Earlier in the day, five of the world's most important central banks, including Canada's, pledged to make it cheaper for European banks to get their hands on U.S. dollars. It's hoped that will improve access to credit everywhere.

The Canadian dollar gained 0.95 of a cent to close at 98.01 US cents. Earlier, it was up as much as 1.72 cents, its biggest intraday jump in 18 months. The loonie also gained on news China was moving to encourage its banks to lend more, amid signs of a slowing economy, and after the Canadian economy grew more than expected in the third quarter.

Virtually every major world currency was higher against the U.S. dollar in reaction to the central banks' move.

The Dow Jones Industrial Average finished with a gain of 490.05 points, or 4.2 per cent, at 12,045.68, its biggest one-day gain since March 2009. The Nasdaq composite index gained 104.83 points, or 4.2 per cent, to 2,620.34 and the S&P 500 index rose 51.77 points, or 4.3 per cent, to 1,246.96.

Oil was also higher, with the January crude contract closing up 57 cents at $100.36 US a barrel in New York. Higher oil prices are largely positive for the TSX, which has a lot of major energy companies listed on it.