BUZZ-Southwest Airlines slips as US sues over chronically delayed flights

Southwest Airlines' LUV.N shares fall 3% to $31.82 premarket

President Joe Biden's administration sues carrier, accusing it of illegally operating multiple chronically delayed flights and disrupting passengers' travel

The U.S. Transportation Department said in its civil suit that for five months in 2022, Southwest operated two chronically delayed flights

The department also said it was fining Frontier Airlines ULCC.O $650,000 for operating multiple chronically delayed flights

Southwest said it was disappointed USDOT chose to sue "over two flights that occurred more than two years ago" and that since 2009, the carrier has operated more than 20 million flights with no other violations

It was unclear whether President-elect Donald Trump's incoming administration would pursue the lawsuit

LUV rose 14.2% in the past 12 months, the worst performing stock in the nine member S&P 1500 passenger airlines index .SPCOMAIR that has risen 77.2%

(Reporting by Medha Singh)

((medha.singh@thomsonreuters.com))