Financing and Debt Unsecured Debt Secured Debt Covenants At December 31, 2011, our unsecured debt consisted of $10.7 billion of senior unsecured notes of the Operating Partnership  and $952.7 million outstanding under the Credit Facility. The December 31, 2011 balance included $287.7 million (U.S. dollar  equivalent) of Yen-denominated borrowings. The maximum outstanding balance of the Credit Facility or the predecessor facility  during the year ended December 31, 2011 was $1.8 billion and the weighted average outstanding balance was approximately  $1.1 billion. Letters of credit of approximately $36.0 million were outstanding under the Credit Facility as of December 31, 2011. On October 5, 2011, we entered into the new Credit Facility replacing a predecessor facility. The Credit Facility provides an  initial borrowing capacity of $4.0 billion, which can be increased at our option to $5.0 billion during its term. The Credit Facility  will initially mature on October 30, 2015 and can be extended for an additional year at our sole option. The base interest rate on  the Credit Facility is LIBOR plus 100 basis points and an additional facility fee of 15 basis points. In addition, the Credit Facility  provides for a money market competitive bid option program that allows us to hold auctions to achieve lower pricing for short-term  borrowings. The Credit Facility also includes a $2.0 billion multi-currency tranche. During the year ended December 31, 2011, the Operating Partnership redeemed at par $542.5 million of senior unsecured  notes with fixed rates ranging from 5.00% to 8.25%. In addition, on November 10, 2011, we issued $500.0 million of senior  unsecured notes at a fixed interest rate of 2.8% with a maturity date of January 2017 and $700.0 million of senior unsecured notes  at a fixed interest rate of 4.13% with a maturity date of December 2021. On January 12, 2010, the Operating Partnership commenced a cash tender offer for any and all senior unsecured notes of  ten outstanding series with maturity dates ranging from 2011 to March 2013. The total principal amount of the notes accepted  for purchase on January 26, 2010 was approximately $2.3 billion, with a weighted average duration of 2.0 years and a weighted  average coupon of 5.76%. The Operating Partnership purchased the tendered notes with cash on hand and the proceeds from an  offering of $2.25 billion of senior unsecured notes that closed on January 25, 2010. The senior notes offering was comprised of  $400.0 million of 4.20% notes due 2015, $1.25 billion of 5.65% notes due 2020 and $600.0 million of 6.75% notes due 2040.  The weighted average duration of the notes offering was 14.4 years and the weighted average coupon was 5.69%. We recorded a  $165.6 million charge to earnings in the first quarter of 2010 as a result of the tender offer. On August 9, 2010, the Operating Partnership commenced a cash tender offer for any and all senior unsecured notes of three  outstanding series with maturity dates ranging from May 2013 to August 2014. The total principal amount of the notes accepted  for purchase on August 17, 2010 was approximately $1.33 billion, with a weighted average duration of 3.5 years and a weighted  average coupon of 6.06%. The Operating Partnership purchased the tendered notes with cash on hand and the proceeds from an  offering of $900.0 million of 4.375% senior unsecured notes that closed on August 16, 2010. The senior notes are due on March  1, 2021. We recorded a $185.1 million charge to earnings in the third quarter of 2010 as a result of the tender offer. Total secured indebtedness was $6.8 billion and $6.6 billion at December 31, 2011 and December 31, 2010, respectively.  During the year ended December 31, 2011, we repaid $368.2 million in mortgage loans with a weighted average interest rate of  6.64%, unencumbering six properties. As discussed in “Acquisitions and Dispositions,” as a result of the acquisition of additional interests in King of Prussia in August  2011, we now own a controlling interest in this property and, accordingly, we consolidated the property as of the acquisition date,  including the property’s $160.1 million mortgage debt. In addition, we consolidated six properties we received as a distribution  from a joint venture of its interests in a portfolio of properties. Four of these properties are encumbered by mortgages totaling  $459.0 million. Our unsecured debt contains financial covenants and other non-financial covenants. If we were to fail to comply with these  covenants, after the expiration of the applicable cure periods, the debt maturity could be accelerated or other remedies could be  sought by the lender including adjustments to the applicable interest rate. As of December 31, 2011, we were in compliance with  all covenants of our unsecured debt. 2011 Annual Report 21