General Electric ( GE) CFO Keith Sherin called concerns about GE Capital "overdone" on Thursday, but concerns about the finance unit continue to weigh on analysts following the stock. GE shares were relatively flat in trading Thursday, but are off more than 57% since the start of this year, much of it due to concerns about GE Capital. Critics fret the unit is not adequately capitalized to withstand potential hits to exposure to Eastern European and commercial real estate and other holdings, which the company has not marked down as aggressively as other finance companies. "They have to come to where the rest of the world is on mark-to-market," says Sterne Agee analyst Nicholas Heymann. Sherin, in a CNBC interview Thursday morning, acknowledged the company may lose its triple-A credit rating. "We're getting a lot of speculation about the risk in GE Capital, obviously, and I think it's overdone," Sherin said on CNBC. "We can basically fund ourselves all the way through 2010 without any issues." Analysts like Heymann are skeptical. GE is projecting losses on its private label credit card business on a model that assumes 9% unemployment. Heyman projects 11% unemployment by the end of the year and says that every 50 basis point increase in unemployment translates to $600 million less in net earnings. Next, is the real estate issue. GE Capital has exposure in Eastern European countries like Hungary and Poland where the payback is now considered to be of very little value. Add to that the real estate decline in the U.K. and Ireland, where GE Capital was a big participant. In the commercial real estate portfolio, rent increases are slowing and actual rents are coming down and the company has yet to accurately reflect the true value of its holdings.