* TSX down 45.19 points, or 0.4 percent, at 12,044.70
* Index weighed by bickering in Europe
* Three biggest sectors all negative to start week
By Alastair Sharp
TORONTO, Aug 20 (Reuters) - Canada’s main stock index dipped lower on Monday, pulled down by shifting signals about the European Central Bank’s plans to tackle the region’s sovereign debt crisis.
The three most influential sectors — financials, materials and energy — were all pushed down after two weeks of gains on a string of positive North American data.
“The tone has weakened this morning again because of Europe, which is the traditional spoiler whenever we seem to get a bit of momentum going,” said Andrew Pyle, a portfolio manager at ScotiaMcLeod.
Germany’s central bank repeated its criticism of the ECB’s bond-buying program, while the ECB sought to quash press speculation about the shape of the plan, saying decisions had not yet been taken.
By 10:20 a.m. (1420 GMT) the Toronto Stock Exchange’s S&P/TSX composite index was down 45.19 points, or 0.4 percent, at 12,044.70.
The biggest weight was Royal Bank of Canada, which slipped 0.8 percent to C$53.56 after four straight sessions of strong gains.
Fertilizer company Potash Corp also dragged the index down, slipping 1.2 percent to C$43.15.
Any signs of weakness in global growth hits the Toronto exchange hard, as it lists an abundance of resource-related companies.
The chief executive of Caterpillar, the world’s largest maker of construction equipment, said the global economic outlook is more uncertain now than at the start of the financial crisis in late 2008.