Reuters reported the United States is likely to signal, perhaps this week, only qualified support for switching to global accounting rules, said a top standards official on Monday.

According to the report, the U.S. Securities and Exchange Commission (SEC) has said it will give more clarity by year-end on whether it will switch to rules authored by the International Accounting Standards Board (IASB) which are used in 120 countries.

Commenting on possible outcomes, IASB Vice Chairman Ian Mackintosh said: "One extreme would be a "big bang" wholesale adoption like in Canada, and the other would be a flat 'No'." Mackintosh noted an SEC paper outlining a possible system of "condorsement" where each IASB rule is adopted individually rather than a wholesale switch -- an idea backed by the trustees of the U.S. Financial Accounting Standards Board (FASB).

As reported, many big U.S. firms are keen to make the switch in order to cut reporting costs as they have many subsidiaries across the world that file statements using IASB rules. However, smaller, domestic-focused U.S. companies and some vocal investor groups say IASB rules are not detailed enough and many in Congress don't want to give up regulatory sovereignty to a body based in London.