The group, which includes Merrill Lynch, Citigroup and Morgan Stanley , among others, could make an announcement about the platform within the next few days, one of the sources said.

Another source said the plans were still very preliminary, though a third said the group was "pretty serious," about the project, which was first reported on the Financial News web site. Financial News also said Credit Suisse, UBS and Deutsche Bank were involved.

The banks declined to comment or could not immediately be reached for comment.

Investment banks currently have to report any trades they make to different exchange authorities across Europe. Some consider the charges, particularly in London, as too high.

"Reporting is complex and fragmented; it's not just about London. Consolidating it in one place makes sense," one of the sources said.

Another pointed to other services, such as Virt-X and Plus Markets Group, which also offer trade reporting services.

JP Morgan and Lehman Brothers are not involved in the plan, the sources said, because they act as brokers to the London Stock Exchange, which currently has the monopoly on collecting sales and trading data in London.

The LSE said it remained confident in its infrastructure.

"We already have an efficient central infrastructure in place for reporting trades," said an LSE spokeswoman. "MiFID (the Markets in Financial Instruments Directive) presents an opportunity for the LSE to capture new business across Europe."