Boeing Willing to Negotiate on Tax Breaks  WASHINGTON/LONDON (Reuters) - Boeing &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=BA.N target=/stocks/quickinfo/fullquote"&gt;BA.N&lt;/A&gt; is prepared to  discuss the elimination of billions of dollars in tax breaks it  receives from Washington state as part of a deal to end  European government loans for its competitor Airbus, the  company's chief executive said on Monday.