$borrar = "<a href="http://us.rd.yahoo.com/dailynews/rss/search/loans/SIG=11lajnv2b/*http%3A//biz.yahoo.com/ap/050323/china_banks_2.html">China to Investigate Bank Loans (Associated Press via Yahoo! Finance)</a>";
//lo q quieras borrar
$path = ereg_replace("<a href="http://us.rd.yahoo.com/dailynews/rss/search/loans/SIG=11lajnv2b/*http%3A//biz.yahoo.com/ap/050323/china_banks_2.html">China to Investigate Bank Loans (Associated Press via Yahoo! Finance)</a>","",$borrar);
//En teoría reemplazaría <a href...> por "", es decir vacío.
Saludos