american tower corporation and subsidiaries notes to consolidated financial statements 2014 ( continued ) customer leases 2014the company 2019s lease agreements with its customers vary depending upon the industry . television and radio broadcasters prefer long-term leases , while wireless communications providers favor leases in the range of five to ten years . most leases contain renewal options . escalation clauses present in operating leases , excluding those tied to cpi , are straight-lined over the term of the lease . future minimum rental receipts expected from customers under noncancelable operating lease agreements in effect at december 31 , 2002 are as follows ( in thousands ) : year ending december 31 .
what portion of future minimum rental receipts is expected to be collected within the next 24 months?
acquisition commitments 2014as of december 31 , 2002 , the company was party to an agreement relating to the acquisition of tower assets from a third party for an estimated aggregate purchase price of approximately $ 74.0 million . the company may pursue the acquisitions of other properties and businesses in new and existing locations , although there are no definitive material agreements with respect thereto . build-to-suit agreements 2014as of december 31 , 2002 , the company was party to various arrangements relating to the construction of tower sites under existing build-to-suit agreements . under the terms of the agreements , the company is obligated to construct up to 1000 towers over a five year period which includes 650 towers in mexico and 350 towers in brazil over the next three years . the company is in the process of renegotiating several of these agreements to reduce its overall commitment ; however , there can be no assurance that it will be successful in doing so . atc separation 2014the company was a wholly owned subsidiary of american radio systems corporation ( american radio ) until consummation of the spin-off of the company from american radio on june 4 , 1998 ( the atc separation ) . on june 4 , 1998 , the merger of american radio and a subsidiary of cbs corporation ( cbs ) was consummated . as a result of the merger , all of the outstanding shares of the company 2019s common stock owned by american radio were distributed or reserved for distribution to american radio stockholders , and the company ceased to be a subsidiary of , or to be otherwise affiliated with , american radio . furthermore , from that day forward the company began operating as an independent publicly traded company . in connection with the atc separation , the company agreed to reimburse cbs for any tax liabilities incurred by american radio as a result of the transaction . upon completion of the final american radio tax returns , the amount of these tax liabilities was determined and paid by the company . the company continues to be obligated under a tax indemnification agreement with cbs , however , until june 30 , 2003 , subject to the extension of federal and applicable state statutes of limitations . the company is currently aware that the internal revenue service ( irs ) is in the process of auditing certain tax returns filed by cbs and its predecessors , including those that relate to american radio and the atc separation transaction . in the event that the irs imposes additional tax liabilities on american radio relating to the atc separation , the company would be obligated to reimburse cbs for such liabilities . the company cannot currently anticipate or estimate the potential additional tax liabilities , if any , that may be imposed by the irs , however , such amounts could be material to the company 2019s consolidated financial position and results of operations . the company is not aware of any material obligations relating to this tax indemnity as of december 31 , 2002 . accordingly , no amounts have been provided for in the consolidated financial statements relating to this indemnification. .