Australia's IDP Education slips after rejecting Blackstone's $494 million bid

** Shares of Australia's IDP Education IEL.AX fall as much as 10.2% to A$1.94, marking their biggest intraday pct loss since August 20

** IELTS English-language exam co-owner rejected roughly A$694.7 million ($493.93 million) takeover proposal from Blackstone BX.N, the company said after market hours on Tuesday

** Blackstone-managed funds offered A$2.50 per share in cash for IDP on September 9, a 56% premium to September 8 close

** Stock jumped nearly 21% in the previous session to close at A$2.16

** IDP board views the offer as substantially undervaluing co and not in the best interests of its shareholders

** Stock down over 65% YTD

($1 = 1.4065 Australian dollars)