AECON GROUP INC 13 Estimated backlog duration As at December 31 millions 2012 2011 Next 12 months 1409 58 1477 62 Next 1324 months 656 27 625 26 Beyond 363 15 288 12 2428 100 2390 100 It is important to note that Aecon does not report as backlog the signifcant and increasing number of contracts and arrangements in hand where the exact amount of work to be performed cannot be reliably quantifed or where a minimum number of units at the contract specifed price per unit is not guaranteed Examples include time and material and some costplus and unit priced contracts where the extent of services to be provided is undefned or where the number of units cannot be estimated with reasonable certainty Other examples include the value of construction work managed under construction management advisory contracts concession agreements multiyear operating and maintenance service contracts supplier of choice arrangements and alliance agreements where the client requests services on an asneeded basis None of the expected revenue from these types of contracts and arrangements is included in backlog Therefore Aecons effective backlog at any given time is greater than what is reported REPORTING SEGMENTS INFRASTRUCTURE Financial highlights Three months ended Year ended millions December 31 December 31 2012 2011 2012 2011 Revenue 6014 5532 18971 19047 Gross proft 546 735 1607 1511 EBITDA 450 584 1057 1104 Adjusted EBITDA 448 574 1047 1058 Operating proft 310 458 595 649 EBITDA margin 75 106 56 58 Adjusted EBITDA margin 74 104 55 56 Operating margin 52 83 31 34 Backlog 1677 1516