Dow Jones to Buy MarketWatch for \$463 Mln  NEW YORK (Reuters) - Dow Jones   Co. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=DJ.N target=/stocks/quickinfo/fullquote"&gt;DJ.N&lt;/A&gt;, publisher of  The Wall Street Journal, has agreed to buy online financial  news provider MarketWatch Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=MKTW.O target=/stocks/quickinfo/fullquote"&gt;MKTW.O&lt;/A&gt; for about \$463 million  in a bid to boost its revenue from the fast-growing Internet  advertising market.