G4S Shares Slide On News That Florida Gunman Was Employee

News that a G4S employee was the gunman who killed 50 people at a packed gay nightclub in Florida wiped almost 200 million pounds ($282.80 million) off the value of the world's largest security firm.

Omar Mateen, 29, a Florida resident and U.S. citizen, had undergone company screening as recently as 2013 with "no findings," his Britain-headquartered employer G4S said on Sunday.

When trading opened in London on Monday, shares in G4S lost 6.6 percent to 175 pence to hit their lowest level since 2009.