For the full year 2019, net income was $206.8 million, or $0.70 per share, based on 294.8 million weighted average diluted shares. This compares to 2018 net income of $221.1 million, or $0.71 per share, based on 310.1 million weighted average diluted shares.
Net sales increased by 0.7% to $1,519.8 million in the fourth quarter of 2019, compared to $1,509.3 million in the prior-year period. The $10.5 million increase was driven by $25.5 million of higher pricing partially offset by $10.8 million of unfavorable volume/mix and $4.2 million of unfavorable foreign exchange.
Net sales increased 2.2% to $6,160.1 million for the full year 2019, compared to $6,029.4 million in the prior-year period. The $130.7 million increase was driven by $131.2 million of higher pricing and $50.2 million of improved volume/mix related primarily to acquisitions. These benefits were partially offset by $50.7 million of unfavorable foreign exchange.
“We are very pleased with our performance and execution in 2019, as well as the positive momentum we have entering 2020,” said Michael Doss, company president and CEO. "In 2019, we continued to build on our paperboard packaging leadership position by investing in our operations and in our people, successfully executing strategic M&A, capturing performance gains and setting the stage for net organic volume growth. Full year 2019 Adjusted EBITDA increased by 6.1% to $1.03 billion, driven primarily by pricing actions and our performance initiatives. We expect to generate 100 to 200 basis points of sustainability supported net organic volume growth in 2020, driven by the conversion of new and existing customers to our paperboard packaging solutions. Graphic Packaging is well-positioned to achieve another year of improved profitability and growth."
Graphic Packaging Holding Company announced that International Paper has notified the company of its intent to begin the process of reducing its ownership interest in Graphic Packaging International Partners, LLC. Per the agreement between the parties, Graphic Packaging will purchase approximately 15.1 million partnership units from International Paper for $250 million. As a result, International Paper's ownership interest in the Partnership will decrease from approximately 21.6% to 18.3%. The purchase will be funded with a draw on Graphic Packaging's domestic revolving credit facility.
“Our strong cash flow generation and healthy balance sheet provide us the flexibility to purchase the initial $250 million of minority interest from International Paper,” Doss said. “The 2018 transaction with International Paper has successfully created value for our customers and stakeholders while building a leading integrated paperboard packaging platform. We appreciate the confidence International Paper placed in us to build and grow the business. The transaction significantly increased our addressable market and vertical integration opportunities, while accelerating our presence in fiber-based packaging solutions."
The company is also announcing the settlement of approximately $900 million in pension obligations related to its largest US pension plan.
EBITDA for the fourth quarter of 2019 was $205.6 million, a decline of $5 million from the fourth quarter of 2018. After adjusting both periods for charges associated with business combinations and other special charges, primarily the pension plan settlement charge in 2019 and the extended Augusta mill outage charge in 2018, Adjusted EBITDA increased $10.7 million to $258.8 million in the fourth quarter of 2019 from $248.1 million in the fourth quarter of 2018. When comparing against the prior-year quarter,
EBITDA for the full year 2019 was $952 million, or $43.9 million higher than the full year 2018. After adjusting both periods for business combinations and other special charges, Adjusted EBITDA increased 6.1% to $1,029.9 million ($1.02 billion) in the full year 2019 from $971 million in the full year 2018.
Net cash provided by operating activities was $665.8 million for the full year 2019, compared to net cash use of $373.8 million during the full year 2018. Total debt (long-term, short-term and current portion) decreased $130 million during the fourth quarter of 2019 to $2,872.8 million compared to the third quarter of 2019.