ING Direct has entered into a sale process to offload part of its mortgage book. The bank is reducing its exposure to the non-branded (or white label) segment of the market and the current sale is one of a number it has made over the past couple of years.News of the sale revived talk that was around the industry a few years ago that ING was getting out of the Australian retail banking market.That is not the case. The bank's strategy is to become the main financial institution for more of its customers.Earlier this year, ING Direct chief executive Vaughn Richtor told Banking Day: "We are transitioning into a primary bank for our customers and focusing on building that relationship with customers, not simply growing assets."Part of that transition involves reducing the bank's exposure to the non-branded lending market - financing mortgage originators who market loans under their own brands.A few years ago, about one-fifth of ING Direct's mortgage portfolio was non-branded lending. Today that proportion is significantly lower.Richtor said ING Direct had made other changes to its mortgage distribution as part of its primary bank strategy, including putting more effort into selling direct through brokers and direct sales.According to the latest APRA data, ING Direct has A$37.6 billion of mortgages on its books. Over the 12 months to May its portfolio has grown 0.9 per cent, which is well below system growth of 6.2 per cent.