Lease Commitments

12 Months Ended

Dec. 31, 2012

Lease Commitments

Lease Commitments

9.    Lease Commitments

        The Company leases office facilities, equipment and automobiles under non-cancelable operating leases. These leases expire at various dates and may contain renewal and expansion options. In addition to base rental costs, occupancy lease agreements generally provide for rent escalations resulting from increased assessments for real estate taxes and other charges. The Company's lease obligations are primarily for the use of office space.

        In November 2011, the Company entered into an agreement to lease office space in a new building to be constructed in London, United Kingdom. The agreement is contingent upon the completion of the building construction. Aon expects to move into the new building in 2015 when the building is completed and it exercises an early break option at another leased facility. The Company has included the future minimum rental payments for this leased space in the schedule below and has excluded the future minimum rental payments for the existing lease beyond the expected date of the exercise of the break option.

        Rental expenses (including amounts applicable to taxes, insurance and maintenance) for operating leases are as follows (in millions):

Years ended December 31	2012		2011		2010
Rental expense	$	536	$	525	$	429
Sub lease rental income		72		71		57
Net rental expense	$	464	$	454	$	372

        At December 31, 2012, future minimum rental payments required under operating leases that have initial or remaining non-cancelable lease terms in excess of one year, net of sublease rental income, are as follows (in millions):

2013	$	432
2014		396
2015		365
2016		332
2017		293
Thereafter		1,072
Total minimum payments required	$	2,890