NEW YORK (AP) _ Canadian Pacific said it is ending its nearly $30 billion takeover bid for rival railroad Norfolk Southern. Norfolk Southern had rejected Canadian Pacific’s bids because it questioned whether regulators would approve it. A deal would have expanded Canadian Pacific’s rail network across the U.S.Calgary, Canada-based Canadian Pacific operates railroads in Canada and parts of the U.S. Midwest and South, while Norfolk Southern of Norfolk, Virginia operates railroads along the East Coast, Midwest and South. Shares of Norfolk Southern Corp. slipped nearly 2 percent in trading before the stock market open Monday. Shares of Canadian Pacific Railway Ltd. were unchanged.