Westpac this week provided an update on the handsome margins it earns on most of its wholesale banking activities in New Zealand.Thanks to a planned transfer involving a number of business activities moving from its foreign bank branch to its incorporated subsidiary, Westpac New Zealand, aspects of the latter's operations have been revealed in the quarterly disclosure statement for the business.Westpac said that as at June 2011 business activities proposed to be transferred included customer loans of around NZ$6.2 billion and customer deposits of approximately $5.8 billion ($5.5 billion at 30 September 2010). The bank said it expected to put term intra-group funding of $3.1 billion in place as well.For the nine months to June 2011, Westpac said it estimated that the business activities being transferred had revenues of around $120 million and enjoyed a net after-tax profit of $74 million.