For the full year 2015, Net Income was $230.1 million, or $0.70 per share, based on 330.7 million weighted average diluted shares. This compares to 2014 Net Income of $89.7 million, or $0.27 per share, based on 330.5 million weighted average diluted shares. Including the tax impact, full year 2015 Net Income was negatively impacted by $16.9 million of special charges (primarily Charges Associated with Business Combinations). When adjusting for these charges, 2015 Adjusted Net Income was $247.0 million, or $0.75 per diluted share, compared to full year 2014 Adjusted Net Income of $238.1 million, or $0.72 per diluted share.
"We delivered a very strong quarter in the face of difficult markets and foreign exchange headwinds," says President/CEO Michael Doss. "Sales increased 2.4% and we continue to gain share in many of our markets. Strong performance drove Adjusted EBITDA Margin higher by 40 basis points to 17.6%. We continued to execute on our operating improvement programs across the organization, achieving $74 million of performance improvements in 2015.
"We've been very busy since the end of the third quarter with the announcement of four strategic tuck-under acquisitions. Investing in high return projects and strategic acquisitions remains a core part of our profitable growth strategy. Two of the acquisitions, Virginia-based Carded Graphics and Minnesota-based Walter G. Anderson, bring state-of-the-art assets and enhance our leadership position in key North American food, beverage and consumer product markets. I am also excited about our international expansions in Mexico and Australia/New Zealand. The G-Box acquisition, completed in early January, adds two strategically located folding carton plants which strengthen our footprint in the growing Mexican food and beverage markets. While Graphic Packaging has been operating successfully in Australia for over two decades, the acquisition of market-leader Colorpak, and its three folding carton manufacturing facilities, allows us to expand in the Australia and New Zealand food, beverage and consumer product markets."
"Graphic Packaging's financial performance and balance sheet have strengthened considerably over the past several years. We are now returning cash to stockholders while maintaining financial flexibility to invest for future profitable growth. During 2015, the Company declared $65 million of dividends and repurchased $63 million of our stock, including $40 million in the fourth quarter. To date in 2016, we have purchased an additional $20 million of stock, increasing share repurchases to $83 million since announcing the $250 million program in February of 2015."
Net Sales increased 2.4% to $1,024.9 million in the fourth quarter of 2015, compared to $1,001.1 million in the prior year period. The $23.8 million increase was driven by $50.4 million of improved volume/mix, related to acquisitions. The sales increase was partially offset by $21.2 million of unfavorable foreign exchange rates and $5.4 million of lower pricing.
Full year 2015 Net Sales decreased 1.9% to $4,160.2 million compared to $4,240.5 million in 2014. The decrease was driven by $221.6 million of lower sales due to business divestitures, $109.0 million from unfavorable foreign exchange rates and $15.6 million of lower pricing. The sales decrease was partially offset by $265.9 million of improved volume/mix, related to acquisitions.