2012 was an excellent year for BRMALLS, with great achievements and exceptional results.
In 2012, we surpassed 50 malls in our portfolio, ending the year with 51 assets, which, according to data from ABRASCE, accounted for over 15% of sales in Brazilian malls. Our malls total GLA accounted for 14.2% of the total GLA in the country in 2012, contributing to further benefits in economies of scale. In 4Q12 total sales reached R$6.3 billion and R$19.6 billion in 2012, increasing 19.5% and 21.6%, respectively. Same store sales recorded 7.6% in the quarter and 7.4% in the year.
In 2012 we completed important mall & media projects, benefiting from the national presence of our portfolio, such as the SulAmérica Seguros campaign, which included 34 malls, and the Mastercard and Redecard campaign, which featured approximately 4 thousand tenants.
Same-mall NOI grew 20.0% in the quarter and 16.4% in the year. In addition to the strong growth of recently opened and acquired malls, we also highlight the performance of mature malls and main generators of the company's NOI, such as Plaza Niterói, Shopping Tijuca and Norte Shopping with same mall NOI in the quarter reaching 22.9%, 23.8% and 17.3%, respectively. The same mall NOI increase in our portfolio was benefited mainly by the same store rent growth of 10.2% in the quarter, and also influenced by the same mall parking revenue growth of 30.1%.
In 2012 the NOI margin ended the year at 91.3%, the largest margin since 2009 and the second highest annual NOI margin of the company. The adjusted EBITDA margin registered 81.0% in 2012, an increase of 1.3p.p compared to 2011 and the highest since 2009.
NOI recorded R$1.0 billion in 2012, increasing 34.0% over the previous year. Adjusted FFO totaled R$420.2 million in the year, growing 27.0%. Net income ex-investment property totaled R$409.5 million in the year, increasing 32.6%.
In 2012 we continued engaged in opportunities to grow our portfolio through development. We developed 119.4 thousand m² of total GLA and 72.6 thousand m² of owned GLA in 3 greenfield projects and 2 expansions, being the major mall developer in the country. In the last 5 years we opened 8 greenfield projects and 10 expansions, adding a total GLA of 330.9 thousand m² and 188.6 thousand m² of owned GLA. The GLA added through development represents 20.4% of our current total GLA and 20.2% of our owned GLA, being an important growth driver for the company.
In our other growth driver, we invested R$635.1 million in acquisitions in 2012. We expect that these acquisitions will generate R$65.0 million in NOI in the first year, representing an entry cap rate of 10.3%. Since 2007 we invested R$5.4 billion in acquisitions.
One of our focuses in 2012, which will continue to be one of our priorities in the following years, is our liability management. Benefiting from a macro backdrop of lower interest rates compared to previous years, BRMALLS refinanced approximately R$850 million of debt in 2012 through the reopening of our second perpetual bond and also by issuing a Real Estate Certificate (CRI). These refinancing activities reduced our average cost of debt and lengthened the duration of our debt. The average cost of debt ended 2012 at IGPM+5.8%, 1.1p.p. lower than the cost of debt in 2011, IGPM +6.9%.
We believe that this liability management, along with a strong and growing cash generation, will allow for a significant increase in the dividends to be paid by the company in the following years. In 2013, BRMALLS will propose to shareholders a dividend payment of R$215.5 million, regarding the 2012 results, an increase of 215.7% compared to the previous year.
In our view, 2013 will be very positive for BRMALLS. We will open a greenfield project and 3 expansions. We will continue to seek growth opportunities through our 3 growth drivers (acquisition, development and organic). In 2013, we will continue with our liability management strategy and will seek opportunities from the economies of scale of our portfolio, enabling a more efficient growth.