Porterbrook Leasing Company Ltd, based in Derby (Derbyshire ) is one of the three major leasing companies for railway vehicles in the UK that have adopted the locomotives, railroad cars, and multiple units as part of the privatization of British Rail in 1996 and the railway companies rent (so-called rolling stock companies or Rosco ).

Porter Brook from 2000 to 2008, a wholly owned subsidiary of Abbey National Bank; after the purchase of Abbey National by Spain's Banco Santander the company from a consortium of financial investors ( including Antin Infrastructure, German Bank and OP Trust ) was acquired.