TORONTO -- Stock markets in both the U.S. and Canada turned positive Tuesday as dovish comments on interest rates by Federal Reserve chairwoman Janet Yellen helped reassure skittish investors.

At mid-afternoon, the S&P/TSX composite index was up 25.56 points at 13,415.75, reversing a triple-digit decline earlier in the day as the May contract for benchmark crude oil slipped for a fourth straight session, down $1.09 at US$38.30 a barrel.

The Canadian dollar, despite the drop in oil prices, added 0.66 of a U.S. cent to trade for 76.53 cents US.

Elsewhere in commodities, April gold rose $18.80 to US$1,238.90 a troy ounce, while May natural gas added five cents to US$1.99 per mmBtu. May copper shed three cents to US$2.21 a pound.

In New York, lacklustre markets picked up after Yellen told the Economic Club of New York that the U.S. central bank expects to move slowly on rate increases because global economic issues could harm the U.S. economy.

The Dow Jones industrial average rose 79.58 points to 17,614.97, while the broader S&P 500 composite soared 14.25 points to 2,051.3 and the Nasdaq shot up 66.97 points to 4,833.76.

Among the Nasdaq winners was Apple (Nasdaq:APPL), which climbed US$2.41 to US$107.60 after the FBI dropped its legal efforts to force Apple to break into the iPhone used by San Bernadino, Calif., shooter Syed Farook, who along with his wife killed 14 people in December. The FBI said it was able to hack into the phone on its own.

In economic news, a new survey showed U.S. consumers were feeling more confident in March, with a rebounding stock market brightening their outlook. The Conference Board said Tuesday that its consumer confidence index rose to 96.2 this month after tumbling to a revised 94 in February.

Overseas, European stocks were mostly higher as trading resumed after markets were closed Easter Monday. France's CAC 40 added 0.85 per cent and Germany's DAX picked up 0.37 per cent, while Britain's FTSE 100 was little changed.

In Asia, Japan's benchmark Nikkei 225 lost 0.18 and China's main Shanghai composite lost 1.28 per cent, while Hong Kong's Hang Seng gained 0.1 per cent.