WASHINGTON (Reuters) – The U.S. Securities and Exchange Commission on Monday proposed new rules for electronic trading platforms for U.S. Treasuries, corporate debt and municipal securities, aimed at improving transparency and operational preparedness in the world’s biggest securities market.

The proposal, which would be subject to public consultation, aims to address concerns about the shift to alternative trading systems (ATS) that trade government securities as well as the repurchase and reverse repurchase agreements on those securities.

The SEC has signaled for years that it planned to hone oversight on the fixed income market even as it put stiffer regulations in place for U.S. equity markets, which have generally been more transparent, industry advocates have said.

Under the new rules, ATS trading platforms will