to satisfy these guarantees. Management concluded that the likelihood of any significant amounts being paid by our Company under these guarantees is not probable. As of December 31, 2010, we were not directly liable for the debt of any unconsolidated entity, and we did not have any retained or contingent interest in assets as defined above. 

Our Company recognizes all derivatives as either assets or liabilities at fair value in our consolidated balance sheets. Refer to Note 5 of Notes to Consolidated Financial Statements. 

As of December 31, 2010, the Company had $4,850 million in lines of credit for general corporate purposes, including commercial paper backup, of which $4,597 million was unused and available. While no amounts have been borrowed against these lines of credit, certain portions have been limited due to outstanding letters of credit related to collateral for claims incurred under our self-insurance programs and for certain operating activities. These backup lines of credit expire at various times from 2011 through 2012. These credit facilities are subject to normal banking terms and conditions. Some of the financial arrangements require compensating balances, none of which is presently significant to our Company. 

The total accrued benefit liability for pension and other postretirement benefit plans recognized as of December 31, 2010, was approximately $2,563 million. Refer to Note 13 of Notes to Consolidated Financial Statements. This amount is impacted by, among other items, pension expense, funding levels, plan amendments, changes in plan demographics and assumptions, and the investment return on plan assets. Because the accrued liability does not represent expected liquidity needs, we did not include this amount in the contractual obligations table. 

The Pension Protection Act of 2006 ("PPA") was enacted in August 2006 and established, among other things, new standards for funding of U.S. defined benefit pension plans. During 2008, the funded status of the Company's primary U.S. defined benefit pension plan declined as a result of the overall stock market decline. In early 2009, the Company contributed approximately $175 million to this plan. Subsequent to this contribution, the plan is sufficiently funded to maintain maximum flexibility as outlined in the PPA. We generally expect to fund all future contributions with cash flows from operating activities. Our international pension plans are generally funded in accordance with local laws and income tax regulations. In 2011, we expect to contribute approximately $800 million to various plans, of which approximately $750 million was contributed in the first quarter of 2011. Approximately half of the expected 2011 contributions will be allocated to our primary U.S. pension plans. Refer to Note 13 of Notes to Consolidated Financial Statements. We did not include our estimated contributions to our various plans in the table above. 

As of December 31, 2010, the projected benefit obligation of the U.S. qualified pension plans was $4,837 million, and the fair value of plan assets was approximately $4,118 million. The majority of this underfunding was due to the negative impact