The proposal would require critically-important entities to satisfy a same-day recovery time objective for trading and clearing as well as geographic dispersal of infrastructure and personnel.

The rule change comes in the wake of the May 6 'flash crash' that paralysed markets when the Dow dropped 1000 points in a day. The self-regulatory body says that business continuity and disaster recovery provisions should be harmonised across both exchanges and clearing organisations to ensure an orderly recovery.

The proposed regulations and amendments will be made available for public comment for 30 days.

The new provisions come as the SEC and CFTC hold the first in a series of meetings to investigate the role played by high frequency traders in the events of 6 May.

CFTC commissioner Scott O'Malia told reporters that some regulation of algorithmic trading and direct market access provisions is "inevitable", but the agency hoped to first gather more information from traders and exchanges by October.

At the meeting, trade database developer Nanex presented analysis that indicated that "quote-stuffing" algorithms designed to prevent other HFTs from executing strategies were in play at the height of the Dow meltdown, as traders sought to make capital from the extreme fluctuations in the market.

CFTC Commissioner Bart Chilton told Reuters the revelations held important implications for market regulators: "If there are algo price pirates out there trying to take advantage of these systems, it's ... a new enforcement regime for us to look at."