Reuters reported that UBS have joined the army of advisers lined up by BHP Billiton for its takeover bid for Rio Tinto and Deutsche Bank has been engaged by Rio to ward off the threat.

According to regulatory filings Deutsche Bank started to reveal daily dealings in BHP and Rio shares on Tuesday because it is advising Rio, and UBS began to publish trading in the companies on the same day as an adviser to BHP.

BHP already has advisers Citigroup, Goldman Sachs, Australian investment bank Gresham Partners and HSBC as well as Merrill Lynch as corporate broker to the company.