North American markets are expected to open slightly lower Tuesday as U.S. investors return from the Memorial Day long weekend.

Here at home, Statistics Canada reported the real gross domestic product grew 0.6% in the first quarter of 2005, a slight acceleration from the previous quarter. In March, economic output declined 0.1% after increasing 0.2% in both January and February.

Later this morning, the U.S. Conference Board is due to release its consumer confidence index for May at 10:00 ET. Economists forecast a moderate decline to 95.8 from 97.7 in April.

As well, the National Association of Purchasing Management-Chicago is slated to release its purchasing managers index at 10:00 ET. Economists expect a fall-off to a reading of 61.0 in May from 65.6 in April.

In financial news, American International Group filed its thrice-delayed annual report with regulators early today. The company had postponed its annual report and other regulatory filings amid multiple and overlapping probes of its accounting by state and federal authorities, first disclosed in February.

In M&A news, Enterra Energy Trust said it is buying oil and gas producer High Point Resources Inc. in a stock-based deal pegged at US$250 million. Under the deal, which includes assumption of US$67 million in debt, High Point shareholders will receive 0.105 of a trust unit of Enterra for each share of High Point.

On Mondya, Toronto stocks closed higher as gains in energy, technology and financial issues helped offset a decline in the utilities group. The S&P/TSX composite index closed up 53.84 points, or 0.56%, at 9,673.20.

The TSX reported its third-straight day of gains, though volume was low with less than 76 million shares traded.

Bank of Nova Scotia shares rose by 14¢, or 0.35%, to $39.69, in anticipation of the release of its second quarter earnings tomorrow.

The junior S&P/TSX Venture composite index was also up for the day, closing ahead by 5.73 points, or 0.35%, at 1,645.91.