TransCanada Pipelines to Acquire Nova

TransCanada Pipelines Ltd. said it will buy Nova Corp. for stock valued at $4.91 billion, a move that would bolster its ability to compete with big U.S. rivals in distributing natural gas through pipelines. The combined company would have a pipeline network extending from Alberta, Canada’s gas fields to the Vermont border. TransCanada and Nova, both based in Calgary, Canada, already distribute most of Canada’s natural gas and want to expand in the U.S. . . . Union Pacific Resources Group Inc. said it agreed to buy Canadian oil and natural gas producer Norcen Energy Resources Ltd. for $2.6 billion in cash. The deal comes two months after Fort Worth-based UPR, the No. 1 U.S. oil and gas driller, abandoned a hostile $4.2-billion bid for Pennzoil Co.