On December 26, 2013, CAAP bought the shares of Abafor S.A., who is a shareholder of CAISA, from Corona Trading Corporation, a subsidiary of Liska. As of September 30, 2017 and December 31, 2016, we owed Corona Trading Corporation U.S.$2.0 million and U.S.$5.3 million, respectively, of the deferred purchase price. For the nine-month period ended September 30, 2017, and the year ended December 31, 2016, we paid interest in the amount of U.S.$0.2 million and U.S.$0.5 million, respectively, on such deferred purchase price amount. We intend to satisfy the deferred purchase price amount payable to Corona Trading Corporation with the proceeds of this Offering.
On June 26, 2015, CASA assigned to CASA Inmobiliaria S.A. its rights against us in respect of our purchase price obligation related to the purchase of ICASGA. These rights were then assigned by CASA Inmobluaria S.A. to OROTUN S.A. on April 12, 2017. For the nine-month period ended September 30, 2017, and the year ended December 31, 2016, we had accrued interest expense of U.S. $0.9 million and U.S.$1.2 million, respectively, in respect of this obligation. As of September 30, 2017 and December 31, 2016, the aggregate amount outstanding under these obligations was U.S. $26.1 million and U.S.$25.2 million, respectively. We intend to pay the purchase price obligation owing to CASA Inmobiliaria S.A. with the proceeds of this Offering.
As of September 30, 2017 and December 31, 2016, related parties owed CAAP and its subsidiaries U.S. $4.9 million and U.S.$8.6 million, respectively, under other related party financing agreements. For the nine-month period ended September 30, 2017, and the year ended December 31, 2016, we had accrued interest income of U.S. $0.1 million and U.S.$0.9 million, respectively, in respect of such related party financing agreements.
Corporación Aeroportuaria S.A.
On December 17, 2007, CASA granted a loan to Unitec Bio S.A., an affiliate which is indirectly controlled by SCF. Upon execution of several amendments to such loan agreement, the aggregate principal amount totaled U.S.$3.5 million. During June 2015, CASA was split off and the loan and other assets and liabilities were transferred to Corporación Aeroportuaria S.A., a shareholder of TAGSA. The loan bears an interest rate of 20%. During the nine-month period ended September 30, 2017, and the year ended December 31, 2016, the accrued interest we recorded in respect of this loan was U.S. $0.2 million and U.S.$0.2 million, respectively. As of September 30, 2017 and December 31, 2016, the total outstanding amount under this loan was U.S.$1.8 million. The loan matures in May 2018.
Other Transactions with Affiliated Companies
ECOGAL Management Support Agreement—Galapagos Airport
On April 15, 2011, ECOGAL, one of our associates, entered into a management support agreement with Corporación América Sudamericana S.A. Sucursal Ecuador (“CASA”), one of our subsidiaries. Pursuant to this management support agreement, CAS collects the fees of ECOGAL under the Galapagos Concession Agreement. Under this Agreement, ECOGAL pays CAS a fee equal to 5% of ECOGAL’s total annual revenue, excluding VAT. During the nine-month period ended September 30, 2017, and the year ended December 31, 2016, ECOGAL accrued, but has not yet paid, CAS an amount of U.S.$0.4 million and U.S.$0.5 million, respectively, for the services provided. As of September 30, 2017 and December 31, 2016, ECOGAL owed CAS U.S. $1.9 million and U.S.$2.1 million respectively.
Know How, Technical and Operational Assistance and Management Agreement—Armenia Airports
On January 1, 2014, AIA and International Airports Management LLC (“IAM”), one of our affiliates, entered into a Know How, Technical and Operational Assistance and Management Agreement which was later amended in April 2014. The agreement will be effective until February 28, 2019.
Pursuant to this agreement, IAM provides AIA management services, as well as know-how, technical and operational assistance in connection with the development of national and international air traffic of passengers, freight and mail, the analysis of operations, ground handling and maintenance activities and budgets, and assistance concerning financial planning and access to financial resources, among other things. AIA pays IAM a fee equal to 5% of the aeronautical revenue of the airport, payable within 30 days of the