TORONTO - The Toronto stock market is in for a tough week as a long-awaited pull back gathered momentum last week amid sliding commodity prices.

"The main issue driving the market is related to the belief that world economic growth is probably once again slowing down," said Luciano Orengo, portfolio manager at Manulife Asset Management.

"You've seen that with rising sovereign debt risk in Europe, the ongoing political instability in the Middle East and the effect that had on oil. That puts a bit of a brake on economic growth."

The TSX tumbled 579 points or four per cent last week in a reversal that didn't seem to surprise analysts.

They pointed out that the market has gone practically straight up without a break since last summer and investors found several good reasons to take some profits.

"It's definitely a breather, a pause for thought that is long overdue," said Andrew Pyle, investment adviser with ScotiaMcLeod in Peterborough, Ont.

Higher oil prices helped sparked the downturn, with prices rising above US$105 during the week as investors worried that unrest in Libya could spread to oil producers in the Persian Gulf, particularly Saudi Arabia.

The surge in oil prices increased worries that higher energy costs would translate into slowing global economic growth.

Prices ended the week at around US$101 a barrel, still up sharply from around US$90 in mid-February, as traders figured the massive earthquake in Japan on Friday would slow demand for crude.

But there was also a realization that oil prices have a new floor and crude won't likely won't be going down to US$90 again any time soon.

"We're definitely building in higher bases here with respect to oil and those higher bases don't stem just from Libya," Pyle said.

"They stem from the fact you do have these structurally stronger demand situations going on in the emerging markets."

Pyle added that despite the uncertainties confronting investors, he's not expecting the drop to turn into something worse.

"For now, this is what I would classify as a breather in the market," he said.

"I don't think these pressures are enough to cause what people fear most: a renewed bear market. In other words, a 20 per cent pullback in the major indices."

At the same time, Manulife's Orengo said it's tough to know what will put markets back on a strong, upward trajectory.

"I think we might be close to a bottom. But you're going to need some positive news to get this market going again and get some more traction," he said.

"I don't know what that is, more good economic news, some large merger and acquisition activity."

It's a slim week for market moving economic data, but investors will be closely watching the U.S. Federal Reserve for their announcement on interest rates on Tuesday.

The U.S. central bank is expected to keep its key interest rate at zero and investors will closely scrutinize its accompanying statement for the Fed's view of the economy.

Despite worries about worsening economic conditions, Pyle said it is highly unlikely the Fed will make any noises about another possible round of stimulus, such as buying up more government bonds.

He pointed out the Fed may be more worried about inflation because of higher energy costs and the effect on other prices.