Security firm G4S, at the center of a political and media storm over its failure to provide enough guards for the London Olympics, said the fiasco would cost it 50 million pounds ($79 million) and it was fighting to rebuild its reputation, Reuters reported.

Under-fire boss Nick Buckles, hauled before British lawmakers last month to explain why troops had to be drafted in to fill the shortfall, pledged on Tuesday, Aug 28, there would be no repeat problems at the Paralympic Games, starting on Wednesday.

He also said there were no signs the company was losing contracts or not winning new ones and that, with 3.8 billion pounds of work per year in its pipeline, it should bounce back.

However, not all analysts were convinced, pointing to the company's decision to freeze its interim dividend, and G4S shares were down over 2 percent in morning trade.

"The unchanged interim dividend suggests some caution from management, especially with a number of key government contract decisions coming up during H2 2012," said Panmure's Mike Allen.

Over half of G4S's British revenue comes from government contracts, with more than 20 percent of its pipeline also stemming from that market, including deals to run prisons and some police services due later this year.

Seymour Pierce analyst Caroline de La Soujeole said Buckles' appearance before parliament's Home Affairs Committee on September 11 could be crucial, ahead of the first wave of prison outsourcing contracts in the autumn.

G4S, with 657,000 staff in over 125 countries, said the findings of a board review into the Olympic contract failure would be available in late September. British lawmakers are also holding an inquiry into the debacle.

The firm said 50 million pounds was its estimate for the cost of paying military and police personnel drafted in to cover the shortfall in guards, as well as potential penalties and liabilities.

G4S managed to provide 7,800 staff for the Olympic Games at peak times, compared with a promised 10,400.

G4S has trimmed its portfolio with business disposals in Sweden and the United States in the first half of the year and said it had also shed 1,100 jobs in the period as part of a restructuring drive to cut annual costs by 30 million pounds.