Westpac New Zealand is confident its decision last year not to join ANZ and ASB in a price war for low deposit mortgages helped it hit the ground running when the Reserve Bank of New Zealand imposed a speed limit on such lending from October 1.Westpac NZ's chief executive, Peter Clare, told Banking Day it had lost about 25 basis points of overall market share in the year to September because it had decided not to compete for high loan-to-valuation ratio mortgages in the first half of the year. This meant Westpac  re-targeted its sales and marketing efforts into the market for mortgages with LVRs of less than 80 per cent earlier than its rivals. This now means it is comfortably inside the RBNZ limit, which requires that no more than 10 per cent of new mortgage flows be above the 80 per cent threshold."We're unashamedly focused on repositioning the business to be more sustainable," Clare said of Westpac's September 2012 decision not to try to match ANZ with discounted offers for high LVR mortgages.Westpac re-assessed the market after the arrival of new RBNZ governor Graeme Wheeler in September and decided the likelihood of forthcoming regulation was high, and Westpac's previously high share of high LVR mortgages required a change, he said."It was beyond regulation. We were starting to see some signs of a property bubble in Auckland, principally, and, to some extent, Christchurch, and we had the highest stock of high LVRs, and I was uncomfortable from a sustainability perspective that we should continue to go head-to-head with our competitors when they were refinancing high LVRs away from us at a very low return on equity," he said."So we've actively walked away from the high LVR business and sought to implement our MyBank strategy in the sub-80 per cent [market]," he said, referring to Westpac's targeting of deals at customers with heavier use of their transaction accounts and more than three other products. Westpac increased its percentage of the 'deeper' MyBank customers to 26.8 per cent in the second half, from 26 per cent in the same half a year ago."That comes at a small cost in market share this year, but I'm extremely confident, given that we're already meeting the LVR speed limits in terms of flow, that we'll be in a position to remain open for business across all the LVR bands in 2013/14."