Investors will be mulling over a big commodity tradings loss by BMO Financial Group and a weaker than expected U.S. economy, when North American markets open Friday.

BMO Financial Group disclosed that it has lost between $350 million and $450 million on natural gas trading. The pre-tax mark-to-market losses will cut second-quarter earnings by 45¢ to 55¢ per share.

The U.S. economy slowed sharply in early 2007, retreating to its weakest pace in four years under the weight of the housing slump.

Gross domestic product rose at a seasonally adjusted 1.3% annual rate January through March, the U.S. Commerce Department said today in the first estimate of first-quarter GDP.

The surprisingly anemic pace lagged the fourth quarter’s rate of 2.5% and reflected the slowest growth in GDP since 1.2% during the first quarter of 2003.

Here at home, manufacturers were more upbeat about their current situation and prospects for production and employment for the second quarter of 2007, Statistics Canada reported today.

The Canadian dollar opened at US89.53¢, up 0.35 of a cent from Thursday’s close.

In earnings news, Microsoft reported a 65% profit rise, buoyed by sales of its new Vista operating system.

In other news, ABN Amro Holding is negotiating to settle a U.S. Justice Department criminal investigation of the bank in the U.S. by paying a record fine of as much as $500 million, even as it seeks to accommodate shareholders who want a bigger say in fast-moving talks about a takeover of the Dutch bank.

On the mergers and acquisition front, Norway’s Statoil agreed to buy oil sands producer North American Oil Sands Corp. for $2.2 billion.

Crude-oil futures rose 11¢ to US$65.17 a barrel, while gold futures dropped US$2.40 to US$675.60 an ounce.

In overseas markets, the Nikkei 225 closed with a 0.2% decline in Tokyo, after the Bank of Japan, as expected, held interest rates at 0.5%.

The FTSE 100 declined 0.5% in London.

Toronto stocks fell Thursday, breaking a string of three straight positive sessions, as a pullback in resource prices drove the market lower.

The S&P/TSX composite index fell 75.33, or 0.55%, to 13,597.52.

The S&P/TSX Venture composite index dropped 17.09 points, or 0.52%, to 3,285.09.

In New York, markets moved modestly forward as investors continued to be pleased with strong corporate earnings news.

The Dow Jones industrial average gained 15.61 points, or 0.12%, to 13,105.50, as the key index pushed further into record territory. In yesterday’s session, the index broke through the 13,000 mark for the first time in its history.

The Nasdaq composite index gained 6.57, or 0.26%, to 2,554.46, and the S&P500 slipped 1.17, or 0.08%, to 1,494.25.