NEW YORK ( TheStreet)-- General Electric ( GE) and Citigroup ( C) are among companies that could see earnings decline by billions of dollars annually--starting in 2012-- if Congress chooses not to extend a loophole that lets U.S. companies avoid taxes on profits earned by overseas finance subsidiaries. Known as the active financing exception, the provision allows companies to avoid taxes on dividend and interest income. Though Congress repealed this loophole in 1986, it was reinstated "temporarily" in 1997, and has been regularly extended since that time, according to Wayne State University Linda Beale writing in her blog, ataxingmatter. However, the last extension ran out at the end of 2011, notes tax consultant Robert Willens, of Robert Willens LLC. The last extension came Dec. 17, 2010. Prior to that, it was Oct. 3, 2008, and prior to that, Congress granted the extension in May 2006. Given the polarized state of Congress and its heated negotiations to avoid the series of drastic cuts known as the "fiscal cliff," Willens is convinced the extension--one of several "tax extenders," that remain in limbo--will have to come in 2013, assuming Congress grants it at all. "Unless this thing gets extended retroactively now for 2012 GE's going to be in a world of hurt because their effective tax rate is going to go up dramatically," Willens says. GE paid a 10.5% tax rate in 2010 and a 20% rate in 2011. The statutory--or default--corporate rate is 35%, though companies rarely pay that much. Willens believes GE's rate would go up to the high twenties without the active financing exemption. Assuming GE added 15% to its tax rate in 2011, the company would have paid an extra $2.86 billion in taxes. Analysts are counting on the laws being extended for GE. In a report published Wednesday, for example, based on a company presentation Monday, Bernstein Research analyst Steven Winoker predicted GE's fourth quarter tax rate would be even lower than the third quarter's 13.8% tax rate, which included a 4.4% rate for GE Capital. A GE spokesman pointed to comments by Chairman and CEO Jeff Immelt during a presentation to investors Monday. "The base case is that the tax laws are extended while tax reformers debate," Immelt said.