text: Enbridge to Buy Some of Shell's Pipelines  TORONTO (Reuters) - Enbridge Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=ENB.TO target=/stocks/quickinfo/fullquote"&gt;ENB.TO&lt;/A&gt; will buy Shell's  Gulf of Mexico natural gas pipelines for \$613 million in a move  that will make it a major transporter in the huge gas-producing  area, Canada's No. 2 pipeline company said on Wednesday.