shares of delta air lines inc dal shed 309 to 3325 thursday on what proved to be an allaround dismal trading session for the stock market with the sp 500 index spx falling 249 to 389575 and dow jones industrial average djia falling 225 to 3320222 delta air lines inc closed 1302 below its 52week high 4627 which the company reached on april 21st the stock demonstrated a mixed performance when compared to some of its competitors thursday as southwest airlines co luv fell 223 to 3729 united