It is reported that shares of Rio Tinto Ltd plunged by 35% on Tuesday after BHP Billiton Ltd. dropped plans to acquire the rival mining giant in a USD 68 billion hostile takeover bid, citing the global economic slowdown and falling commodity prices.

In late morning trading Tuesday, Rio's shares fell $50.79, or nearly 35 percent, to $95.20 while BHP's stock rose $4.79, or 14 percent, to $38.17.

Melbourne-based BHP launched a hostile, all-stock bid in February, offering 3.4 BHP shares for every share of London-based Rio Tinto in a deal then valued at about $147 billion. But the stock prices of the two companies have plummeted since then along with global markets, and the bid's value shrank to around $68 billion.