* Energy group up 8.1 percent, leads index higher
* All 10 groups rise, building on last's week's gains (Adds details)
TORONTO, Oct 20 (Reuters) - The Toronto Stock Exchange's main index jumped 3.8 percent in a broad-based rally on Monday morning as higher commodity prices pulled up the energy and materials sectors.
Oil was up, but off session highs around $73 a barrel, supported by expectations that OPEC may cut output this week to boost prices, [ID:nSYD4652]. The Toronto oil and gas sector was up 8.1 percent.
The materials sector, which includes miners, also pushed higher as prices for gold and other metals rose.
Shortly after 10:00 a.m. (1400 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was up 367.42 points, or 3.8 percent, to 9,929.91. All 10 of the index's main groups were in positive territory.
The gains build on a strong finish from the previous week when the index snapped a three-week losing streak with a 5.5 percent weekly rise, its biggest such gain since October 2002.
$1=$1.19 Canadian Reporting by Ka Yan Ng; Editing by Peter Galloway