** Shares of U.S. carrier Spirit Airlines slide 62.4% to $1.22 premarket

** Spirit Airlines is preparing to file for bankruptcy protection after merger talks with Frontier Airlines broke down, the Wall Street Journal reported on Tuesday

** Spirit said it is in talks with creditors and continues to explore strategic alternatives to improve liquidity

** If the agreement fails, it will lead to the cancellation of existing equity and co will consider all alternatives

** Co said Q3 adj operating margin would be down 12% from last year

** Spirit has failed to report a profit in the last five out of six quarters

** As of last close, stock down 79.8% YTD

(Reporting by Sukriti Gupta in Bengaluru)

((Sukriti.Gupta@thomsonreuters.com;))