FAILING sub-prime mortgages have claimed their first US bank — online lender NetBank was shut down by US Government regulators at the weekend.

Soaring defaults of home loans given to poor-quality borrowers in the US have closed dozens of mortgage companies and stressed British bank Northern Rock, but web-only lender NetBank is the first federally regulated bank in the US to go to the wall.

The Federal Deposit Insurance Corporation (FDIC) was named receiver by the Office of Thrift Supervision, NetBank's primary regulator. With about $US2.5 billion ($A2.8 billion) in assets, NetBank is the 58th-largest bank failure in FDIC history.