Firms in the FSCS's investment intermediation sub-class are likely to have to pay an interim levy of £93m in just 30 days, to cover the cost of claims against investment firms including Keydata.
Including firms in the investment fund management sub-class, the total interim levy for 2010/11 will likely hit £326m.
This will be made up of £7m management expenses and £319m compensation costs.
The FSCS is raising the levy, which comes on top of its annual levy, to cover the costs of claims against Keydata Investment Services, Wills & Co and other investment intermediary firms.
About £247m of the costs are for claims against Keydata. The FSCS says the company's collapse represents the biggest investment failure it has ever dealt with.
According to the FSCS, a levy of £96m will trip the annual £100m threshold for the investment intermediation sub-class, meaning the investment fund management sub-class is expected to contribute.
The FSCS makes clear any recoveries are attributed to the class or sub-class they relate to and are used to reduce future compensation costs.
Mark Neale, the chief executive of the FSCS, says: "We fully recognise the levy will come during what are undoubtedly difficult times for many firms.
"But we have a duty to compensate consumers who have eligible claims and need to levy the industry for the continuing costs of the failures so we can protect investors.
"No matter how difficult it may be, we have to meet our obligations to consumers."
The move comes ahead of the FSCS plan and budget for 2011/12, which is due in February. That will provide the scheme's estimate of claims, compensation costs and potential levies for the coming financial year.
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