Former Citigroup Inc. (NYSE: C) chief executive Sanford I. Weill, one of the most important players in the deregulatory push of the 1990s that repealed the Glass-Steagall Act and allowed the formation of too big to fail banks, said Wednesday on CNBC the nation's financial supermarkets should be split up by government mandate.

What we should probably do is go and split up investment banking from banking, have banks be deposit takers, have banks make commercial loans and real estate loans, have banks do something that's not going to risk the taxpayer dollars, that's not too big to fail, Sanford said during the first half of a two-hour appearance, essentially endorsing the rollback of banking regime changes he had pushed for in the late 1990s.

Weill went even further than suggesting the re-instatement of something akin to the Glass-Steagall Act, saying banks should operate with a leverage ratio of 12 times to 15 times of what they have on their balance sheets, clear market transactions on a nightly basis and eliminate anything but the most straightforward of accounting methods.

There should be no such thing as off balance sheet, he said.

Weill admitted the move would completely change the character of Wall Street, as the main institutions currently behind the American capital markets will just be bigger regional banks if his suggestions are adopted.

Responding to the somewhat shell-shocked response by CNBC host Andrew Ross Sorkin that the plan he was suggesting would run into massive political opposition push Weill replied, I'm saying push them in a different way. Push them apart and make it work.

Weill's policy position is a stunning turnaround at a personal level. In his biography, Weill once boasted the Gramm-Leach-Bliley Act, which repealed Glass-Steagall -- and which he is suggesting should now be discarded -- should have been called the Weill-Gramm-Leach-Bliley Act.

Weill said he had changed his position about the industry because the world changes.

The world we live in now is not the world we lived in 10 years ago, Weill said. Good things are simple.