(1) Combined results for HomeStreet and Windermere Mortgage Services Series LLC.
Single family mortgage interest rate lock commitments in 2012, net of estimated fall out, totaled $4.79 billion, up from $1.77 billion in 2011. Rate lock commitments were $1.25 billion in the fourth quarter, up $711.8 million, or 131%, from the fourth quarter of 2011 and down $58.2 million, or 4.4%, from the third quarter of 2012. We believe that the decline in rate lock commitments in the fourth quarter of 2012 compared to the third quarter of 2012 was primarily the result of a decline in loan activity typical of the holiday season, which was partially offset by the continued expansion of our mortgage lending personnel and production capacity.
Single family closed loan volume designated for sale totaled $4.67 billion for 2012, up from $1.70 billion in 2011. The fourth quarter closed loan volume was $1.52 billion, increasing $894.9 million, or 143%, from the fourth quarter of 2011, and increasing $150.7 million, or 11.0%, from the third quarter of 2012. At December 31, 2012, the combined pipeline of rate lock commitments, net of estimated fallout, and mortgage loans held for sale was $1.18 billion, compared to a total pipeline of $1.25 billion at September 30, 2012, reflecting a reduction in rate lock commitments in the fourth quarter of 2012 which we believe reflects a seasonal decline in loan activity typical of the holiday season, partially offset by increased mortgage production capacity. The Company continues to grow its mortgage origination and production capacity, and increased its mortgage lending and support personnel by 10.8% in the fourth quarter and 146% during 2012.
Net gain on mortgage loan origination and sale activities in the fourth quarter of 2012 was $68.8 million, an increase of $49.8 million, or 262%, over the fourth quarter of 2011 and $210.2 million for the full year, up from $48.5 million in 2011. Increased mortgage loan origination and sale revenue reflects continued strong demand for both purchase and refinance mortgage loans in our markets, including refinances through the federal government's expanded Home Affordable Refinance Program (“HARP 2.0”), primarily driven by continuing low mortgage interest rates as well as strong secondary market profit margins that persisted the entirety of 2012. Due to differences in the timing of revenue recognition between components of the gain on loan origination and sales activities, the Company analyzes the profitability of these activities using a 'Composite Margin,' which is comprised of the ratios of the components to their respective populations of interest rate lock commitments, loans closed and loans sold. The Composite Margin for the fourth quarter was 494 basis points, up from 493 basis points in the prior quarter (see the Mortgage Banking Activity table for details). HARP 2.0 refinances represented approximately 19% of loans originated in the fourth quarter of 2012. Overall, single family mortgage production was comprised of 32% purchases and 68% refinances in the fourth quarter of 2012.