After last summer's Olympics fiasco and a warning that 2013 would yield lower-than-expected profits, security firm G4S announced on Tuesday that chief executive Nick Buckles would step down at the end of May.
The firm's chief financial officer, Ashley Almanza, will replace Buckles. Shares of G4S rose 1.24 percent on Tuesday morning following the news.
Buckles, who was a key figure in the merger of Securicor and Group 4 Falck in 2004, ended his 28-year tenure at the firm after the world's largest security group issued a profit warning on May 7 that sent its shares tumbling 13 percent.
G4S blamed the weak trading conditions on difficult client relations in Africa and the closure of 30 prisons in the Netherlands, forcing it to cut 700 jobs.
(Read More: G4S Fights Back After 'Very Tough' Olympics Fiasco)
G4S became the center of a media storm in the run-up to the 2012 London Olympics when the firm failed to hire and train enough security guards for the Games. The government was forced to call in the army to shore up security. Buckles described the company's failure as a "humiliating shambles" and the firm was forced to pay 88 million pounds ($135 million) to the government.
Buckles had managed to ride out previous storms. In 2011, he survived a shareholder revolt, following the failure to buy ISS, a Danish cleaning services group.