The securities regulator is in talks with major Wall Street banks to settle fraud allegations relating to the sale of toxic mortgage bonds to various investors that helped unleash the financial crisis, the Wall Street Journal reported, citing sources familiar with the matter.

The first settlement with the Securities and Exchange Commission (SEC) could be reached as soon as next week, while some of the other deals could take months to work out, the WSJ said.

SEC's negotiations with the banks include JPMorgan Chase, Citigroup Inc, Morgan Stanley, Merrill Lynch, now an unit of Bank of America, and UBS, according to the Journal.

The SEC hopes to reach a series of settlements with individual banks over the sales of mortgage bonds, rather than a big industry wide deal, the Journal said, citing people familiar with the matter.

The regulator's decision to go for individual settlements reflects substantial differences in the nature of the civil fraud allegations faced by each bank, the sources told the Journal.

All of the banks named in the report and the SEC declined to comment to WSJ.

Spokesmen for JPMorgan and Bank of America Merrill Lynch declined to comment on the Journal report to Reuters . All other parties could not immediately be reached for comment outside regular U.S. business hours.

(Reporting by Sakthi Prasad in Bangalore; Editing by Dhara Ranasinghe)