More than half of Commonwealth Bank's crook loans in the construction and property sectors were originated by Bank of Western Australia, CBA's quarterly "pillar 3" disclosure document, also published yesterday, shows.The two sectors account for 29 per cent of the bank's $4.2 billion in impaired loans, and 27 per cent of the bank's specific provisions of $1.7 billion at June 2009.Overall the addition of BankWest (purchased in December 2008) boosted CBA's impaired loans by 48 per cent as of June 2009, and lifted the specific provision by 29 per cent to $2.6 billion.Actual losses incurred by BankWest, however, were only $27 million according to an analysis of impairments by industry sector published by the bank. CBA racked up another $980 million in losses.Leaving aside the bank of origin of the lending losses, more than 40 per cent were classed as "other personal", 16 per cent as "other finance" and nine per cent as manufacturing.The "other finance" sector was an area of lending where Commonwealth Bank, and not BankWest, drummed up the problem customers. CBA listed $580 million in impaired loans to this sector.CBA also found some bank counterparties to lose money through. There were $246 million of impaired loans to banks of which $26 million turned into losses.A separate analysis of lending losses (which does not fully reconcile to the table used in the preceding discussion) shows that of $1.14 billion in losses over 2009, $553 million, or almost half, were classed as corporate, $294 million as "qualifying revolving retail", meaning mainly credit cards, and $216 million as other retail. Twelve months earlier, corporate lending losses were 20 per cent of CBA's actual losses.