UPS Eyes China Domestic Service  HONG KONG (Reuters) - United Parcel Service Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=UPS.N target=/stocks/quickinfo/fullquote"&gt;UPS.N&lt;/A&gt;,  the world's largest package delivery firm, said on Friday that  it is evaluating China's domestic express market but is  concerned about the country's proposed postal legislation.