Washington Mutual Inc. (WM) has either suspended or cut down a total of $6 billion in available home equity lines of credit in the latest effort by a major bank to reduce its exposure to the mortgage mess. The cuts, which were first reported last week by National Mortgage News, affect an unknown number of customers; the bank has declined to identify the number of affected customers to the press. Most customers have already been notified of the cuts, a representative confirmed; letters detailing the changes were mailed to affected customers last week. The pullback does not affect home equity loans. The move by Washington Mutual comes as second liens enter into focus as the latest source of losses for lenders amid an evolving mortgage and housing crisis that is forcing widespread drops in housing prices. Bank of America Corp. (BAC) executives confirmed last week that expected losses on its $118 billion portfolio of HELs would outstrip earlier expectations, while Moody's Investors Service riled up the market's largest monoline bond insurers by suggesting that increasing losses on subprime seconds may put their core credit ratings at risk for a downgrade. It's unclear at this point if the cut by WaMu was defensive, and an attempt to stem future expected losses, or a reaction to rising losses being observed already in its HELOC portfolio. The Seattle-based bank held $61.2 billion in home equity loans and home equity lines of credit at the end of the first quarter; charge-offs on the banks HEL/HELOC portfolio reached $486 million in Q1, compared to $249 million in Q4, underscoring just how quickly home equity lending had headed south at the bank. Disclosure: The author held no positions in WM or BAC when this story was originally published. HW reporters and writers follow a strict disclosure policy, the first in the mortgage trade.