North American markets are likely to climb at Monday’s open, helped by a batch of merger announcements.

As well, traders are gearing up for another round of corporate earnings releases.

Valero Energy agreed to acquire refiner Premcor for US$6.9 billion in cash and stock plus the assumption of about US$1.8 billion of debt — a move that would create the largest refiner of crude oil in North America.

Internet advertising company DoubleClick announced today it has agreed to be acquired by private-equity firm Hellman & Friedman for about US$1.1 billion.

Verizon is widely expected to boost its bid for MCI Inc. again now that the long-distance phone company has embraced a rival US$9.75 billion bid from Qwest, though it remains unlikely Verizon will need to pay that much to win MCI back.

There are no major economic announcements from Statistics Canada today. South of the border, the National Association of Realtors is due to report on existing home sales at 10:00 ET. Economists look for existing home sales to hold steady in March at an annual rate of 6.77 million, easing 0.3% from the prior month.

On Friday, Toronto stocks closed broadly lower as fears of higher interest rates offset buoyant commodity prices .The S&P/TSX composite index closed down 38.29 points, or 0.41%, at 9,367.49.

Inflation data released on Friday, coupled with strong retail sales this week, sparked talk that the Bank of Canada may raise interest rates sooner rather than later.

On Wall Street, U.S. stocks closed lower, hit by higher crude oil prices, a report that North Korea could be preparing for a nuclear weapons test and some disappointing earnings from companies like Costco .

The Dow Jones industrial average was down 60.89 points, or 0.60%, to end at 10,157.71 and the S&P 500 was down 7.83 points, or 0.68%, to close at 1,152.12. The tech-heavy Nasdaq composite index was down 30.22 points, or 1.54%, to finish at 1,932.19.

For the week, the Dow ended up 0.71%, the S&P 500 edged up 0.84%, and Nasdaq was up 1.26%.