United Dominion Buys \$897 Million Homes  NEW YORK/BOSTON (Reuters) - United Dominion Realty Trust  Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=UDR.N target=/stocks/quickinfo/fullquote"&gt;UDR.N&lt;/A&gt;, one of the largest U.S. apartment owners, said on  Tuesday it plans to buy \$897 million worth of apartment homes,  moving from lower-rent housing to more expensive properties  based mainly in fast-growing Southern California.