Bloomberg reported today that U.S. banks may face more than $100 billion in costs as more investors demand that issuers of mortgage-backed securities repurchase bad loans.

According to Paul Miller of FBR Capital Markets, U.S. banks such as JPMorgan Chase & Co. and Bank of America Corp. could face a price tag between $54 billion and $106 billion. Two months ago, Miller estimated the losses to be between $44 billion and $91 billion. The increase reflects the liabilities that will rest with issuers of the securities and banks being more forthcoming about possible losses, according to the Bloomberg article.

Analysts have differed on how much mortgage buybacks may cost banks as Fannie Mae and Freddie Mac are pressuring lenders to repurchase loans that may have been based on inaccurate data. Private investors in mortgage-backed securities are also pursuing claims. On November 4, Standard & Poor’s told investors that total losses would reach $43 billion by 2012.

As for the high end of his estimate, Miller said that the $106 billion figure would be the worst-case scenario for banks and that he does not see the losses being that high. Further, he said, most of the increase in his estimated losses would come from demands to “private label” issuers, which are subsidiaries of investment banks, financial institutions and home builders that are not government-sponsored entities.