rate was determined. Return on assets assumptions for international pension and other post-retirement benefit plans are calculated on a plan-by-plan basis using plan asset allocations and expected long-term rate of return assumptions. The weighted average expected return for the international pension plan is 6.38% for 2012, compared to 6.58% for 2011.

 

For the year ended December 31, 2011, the Company recognized total consolidated pre-tax pension and postretirement expense (after settlements, curtailments and special termination benefits) of $555 million, up from $322 million in 2010. Pension and postretirement expense (before settlements, curtailments and special termination benefits) is anticipated to increase to approximately $644 million in 2012, an increase of $89 million compared to 2011. For the pension plans, holding all other factors constant, a 0.25 percentage point increase/decrease in the expected long-term rate of return on plan assets would decrease/increase 2012 pension expense by approximately $30 million for U.S. pension plans and approximately $12 million for international pension plans. Also, holding all other factors constant, a 0.25 percentage point increase in the discount rate used to measure plan liabilities would decrease 2012 pension expense by approximately $37 million for U.S. pension plans and approximately $16 million for international pension plans. In addition, a 0.25 percentage point decrease in the discount rate used to measure plan liabilities would increase 2012 pension expense by approximately $39 million for U.S. pension plans and approximately $19 million for international pension plans.

 

Asset Impairments:

 

As of December 31, 2011, net property, plant and equipment totaled $7.7 billion and net identifiable intangible assets totaled $1.9 billion. Management makes estimates and assumptions in preparing the consolidated financial statements for which actual results will emerge over long periods of time. This includes the recoverability of long-lived assets employed in the business, including assets of acquired businesses. These estimates and assumptions are closely monitored by management and periodically adjusted as circumstances warrant. For instance, expected asset lives may be shortened or an impairment recorded based on a change in the expected use of the asset or performance of the related asset group. Impairments recorded in 2009 related to restructuring actions are discussed in Note 4.

 

In June 2009, 3M’s Security Systems Division (within the Safety, Security and Protection Services business segment) was notified that the UK government decided to award the production of its passports to a competitor upon the expiration of 3M’s existing UK passport contracts in October 2010. As a result of this event, in June 2009, 3M tested the long lived assets associated with the UK passport activity for recoverability and also reassessed their remaining useful lives. In addition, 3M tested goodwill for impairment at the reporting unit (Security Systems Division) level. The result of the June 2009 test of recoverability of long lived assets associated with the UK passport activity indicated that the