An association of the world's financial institutions is urging governments to better coordinate their banking rules.

The Institute of International Finance warns banking regulation among the Group of 20 most powerful economies remains fragmented. IIF head Tim Adams says in a letter that "unilateral regulation... threatens to reverse recent progress toward a more coordinated system."

Countries are tightening bank regulation to avoid a repeat of the 2007-2008 financial crisis. Efforts are under way in the United States, Britain and other countries in the European Union.

The IIF says countries need similar rules to create a level playing field and avoid the possibility banks will move to less regulated jurisdictions. The group, based in Washington DC, counts banks, hedge funds, insurance companies and other financial institutions as its members.