the following were issued in 2007 : 2022 sfas 141 ( r ) , 201cbusiness combinations 201d 2022 sfas 160 , 201caccounting and reporting of noncontrolling interests in consolidated financial statements , an amendment of arb no . 51 201d 2022 sec staff accounting bulletin no . 109 2022 fin 46 ( r ) 7 , 201capplication of fasb interpretation no . 46 ( r ) to investment companies 201d 2022 fsp fin 48-1 , 201cdefinition of settlement in fasb interpretation ( 201cfin 201d ) no . 48 201d 2022 sfas 159 the following were issued in 2006 with an effective date in 2022 sfas 157 2022 the emerging issues task force ( 201ceitf 201d ) of the fasb issued eitf issue 06-4 , 201caccounting for deferred compensation and postretirement benefit aspects of endorsement split-dollar life insurance arrangements 201d status of defined benefit pension plan we have a noncontributory , qualified defined benefit pension plan ( 201cplan 201d or 201cpension plan 201d ) covering eligible employees . benefits are derived from a cash balance formula based on compensation levels , age and length of service . pension contributions are based on an actuarially determined amount necessary to fund total benefits payable to plan participants . consistent with our investment strategy , plan assets are primarily invested in equity investments and fixed income instruments . plan fiduciaries determine and review the plan 2019s investment policy . we calculate the expense associated with the pension plan in accordance with sfas 87 , 201cemployers 2019 accounting for pensions , 201d and we use assumptions and methods that are compatible with the requirements of sfas 87 , including a policy of reflecting trust assets at their fair market value . on an annual basis , we review the actuarial assumptions related to the pension plan , including the discount rate , the rate of compensation increase and the expected return on plan assets . the discount rate and compensation increase assumptions do not significantly affect pension expense . however , the expected long-term return on assets assumption does significantly affect pension expense . the expected long-term return on plan assets for determining net periodic pension cost for 2008 was 8.25% ( 8.25 % ) , unchanged from 2007 . under current accounting rules , the difference between expected long-term returns and actual returns is accumulated and amortized to pension expense over future periods . each one percentage point difference in actual return compared with our expected return causes expense in subsequent years to change by up to $ 7 million as the impact is amortized into results of operations . the table below reflects the estimated effects on pension expense of certain changes in annual assumptions , using 2009 estimated expense as a baseline . change in assumption estimated increase to 2009 pension expense ( in millions ) .
what was the change in the expected long-term return on plan assets for determining net periodic pension cost in 2008 compared to 2007?
( a ) de minimis . we currently estimate a pretax pension expense of $ 124 million in 2009 compared with a pretax benefit of $ 32 million in 2008 . the 2009 values and sensitivities shown above include the qualified defined benefit plan maintained by national city that we merged into the pnc plan as of december 31 , 2008 . the expected increase in pension cost is attributable not only to the national city acquisition , but also to the significant variance between 2008 actual investment returns and long-term expected returns . our pension plan contribution requirements are not particularly sensitive to actuarial assumptions . investment performance has the most impact on contribution requirements and will drive the amount of permitted contributions in future years . also , current law , including the provisions of the pension protection act of 2006 , sets limits as to both minimum and maximum contributions to the plan . we expect that the minimum required contributions under the law will be zero for 2009 . we maintain other defined benefit plans that have a less significant effect on financial results , including various nonqualified supplemental retirement plans for certain employees . see note 15 employee benefit plans in the notes to consolidated financial statements in item 8 of this report for additional information . risk management we encounter risk as part of the normal course of our business and we design risk management processes to help manage these risks . this risk management section first provides an overview of the risk measurement , control strategies , and monitoring aspects of our corporate-level risk management processes . following that discussion is an analysis of the risk management process for what we view as our primary areas of risk : credit , operational , liquidity , and market . the discussion of market risk is further subdivided into interest rate , trading , and equity and other investment risk areas . our use of financial derivatives as part of our overall asset and liability risk management process is also addressed within the risk management section of this item 7 . in appropriate places within this section , historical performance is also addressed. .