Air Canada to Buy 30 Bombardier Jets  MONTREAL (Reuters) - Air Canada has agreed to buy 30  Canadair Regional Jets from Bombardier Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=BBDb.TO target=/stocks/quickinfo/fullquote"&gt;BBDb.TO&lt;/A&gt; in a  contract valued at \$821 million, the companies said on Monday,  but the order falls 15 jets short of an earlier plan.