MGM Resorts shares tumble after Diller's People withdraws $18 billion bid

Shares of MGM Resorts NYSE:MGM slid 9% on Thursday after media mogul Barry Diller's People Inc NASDAQ:PPLI withdrew its more than $18 billion proposal to buy the casino operator.At $34.40 in premarket trading, MGM's stock was on track for its lowest open in seven months, if losses hold, and the slu…