required cleanup, the interpretation of applicable laws and regulations, and alternative cleanup methods. As of December 27, 2024, we concluded that we would incur investigation and remediation costs at these sites in the reasonably possible range of $18 million to $43 million, and we accrued $21 million as the probable loss, which was the best estimate within this range. We believe that any potential payment of such estimated amounts will not have a material adverse effect on our results of operations, financial position, or cash flows.
Guarantees
In disposing of assets or businesses, we often provide representations, warranties, and/or indemnities to cover various risks including unknown damage to assets, environmental risks involved in the sale of real estate, liability for investigation and remediation of environmental contamination at waste disposal sites and manufacturing facilities, and unidentified tax liabilities and legal fees related to periods prior to disposition. We do not expect that these uncertainties will have a material adverse effect on our results of operations, financial position, or cash flows.
At December 27, 2024, we had outstanding letters of credit, letters of guarantee, and surety bonds of $185 million, including letters of credit of $22 million associated with our divestiture of the Subsea Communications business. In addition, as of December 27, 2024, we had $23 million of performance guarantees associated with the divestiture. We contractually agreed to continue to honor letters of credit and performance guarantees related to the business’ projects that existed as of the date of sale; however, based on historical experience, we do not anticipate having to perform on these guarantees.
Supply Chain Finance Program
We have an agreement with a financial institution that allows participating suppliers the ability to finance payment obligations. The financial institution has separate arrangements with the suppliers and provides them with the option to request early payment for invoices. We do not determine the terms or conditions of the arrangement between the financial institution and suppliers. Our obligation to suppliers, including amounts due and scheduled payment dates, are not impacted by the suppliers’ decisions to finance amounts under the arrangement and we are not required to post collateral with the financial institution. The outstanding payment obligations under our supply chain finance program, which are included in accounts payable on our Condensed Consolidated Balance Sheets, were $126 million and $105 million at December 27, 2024 and September 27, 2024, respectively.
10. Financial Instruments
Foreign Currency Exchange Rate Risk
As part of managing the exposure to changes in foreign currency exchange rates, we utilize cross-currency swap contracts and foreign currency forward contracts, a portion of which are designated as cash flow hedges. The objective of these contracts is to minimize impacts to cash flows and profitability due to changes in foreign currency exchange rates on intercompany and other cash transactions. We expect that significantly all of the balance in accumulated other comprehensive income (loss) associated with the cash flow hedge-designated instruments addressing foreign exchange risks will be reclassified into the Condensed Consolidated Statement of Operations within the next twelve months.
Hedge of Net Investment
We hedge our net investment in certain foreign operations using intercompany loans and external borrowings denominated in the same currencies. The aggregate notional value of these hedges was $2,324 million and $2,417 million at December 27, 2024 and September 27, 2024, respectively.
We also use a cross-currency swap program to hedge our net investment in certain foreign operations. The aggregate notional value of the contracts under this program was $6,138 million and $5,367 million at December 27, 2024 and September 27, 2024, respectively. Under the terms of these contracts, we receive interest in U.S. dollars at a weighted-average rate of 2.0% per annum and pay no interest. Upon the maturity of these contracts at various dates through fiscal