The BNZ figures change considerably the provisional market share figures for the other three major mortgage lending banks. Using Reserve Bank figures as a proxy for the market, ANZ/National had seemed to lift its market share in the September quarter while ASB Bank and Westpac's market shares had appeared to be steady.

With the figures of all mortgage-lending banks, including BNZ, now available, ANZ/National Bank's actual market share eased to 34.31% from 34.42% at the end of June and compared with 34.86% in September 2006. That's even though its mortgage book grew by $1.5 billion in the three months ended September, taking the total to $49.51 billion.

ASB's market share dipped to 22.62% in September from 23.87% in June and from 24.13% in September 2006, even though its mortgage book grew by $790 million to $34.09 billion in the three months ended September 2007.

Westpac, whose mortgage book grew by $640 million in the September quarter to $28.99 billion, saw its market share slip to 20.09% from 20.32% at the end of June but that was still up from 19.63% in September 2006.

BNZ's net profit rose 11.5% to $175 million in the September quarter, bringing its annual result to $683 million, up 12.9% on the previous year.

As expected, Kiwibank's market share surged in the quarter, mostly reflecting its purchase of nearly $700 million of AMP-branded mortgages from HSBC - the latter's mortgage book also shrank for the same reason.

Kiwibank's mortgage book grew by $820 million to $4.23 billion in the three months ended September, taking its market share to 2.93% from 2.49% at the end of June and compared with 2.19% in September last year. (The figures for the June quarter have been revised, reflecting the bank's adoption of the new International Financial Reporting Standards.

Kiwibank's net profit rose 29% to $11.43 million compared with the September quarter of 2006.

HSBC's mortgage market share slipped to 0.96% from 1.51% in June and 1.55% in September last year. It's net profit for the September quarter jumped 27.9% to $9.21 million.

TSB Bank's mortgage share remained steady on 1.25% as its mortgage book grew to $1.8 billion at September 30 from $1.75 billion at June 30. It's net profit rose 16% to $10.9 million compared with the September quarter of 2006.