| | December 31, 2017 | | | December 31, 2016 | | ||||||||||
| | Ownership interest | | | Book value | | | Ownership interest | | | Book value | | ||||
Associates | | | | | | | | | | | | | | | | |
A.C.H Colombia S.A. | | | 34 | % | | Ps. | 12,357 | | | | 34 | % | | Ps. | 10,467 | |
Redeban Multicolor S.A. | | | 20 | % | | | 19,529 | | | | 20 | % | | | 18,421 | |
Credibanco (*) | | | 25 | % | | | 196,071 | | | | 25 | % | | | 192,893 | |
Aerocali S.A. | | | 50 | % | | | 17,633 | | | | 50 | % | | | 24,971 | |
Colombiana de Extrusión S.A. Extrucol | | | 30 | % | | | 11,476 | | | | 30 | % | | | 11,354 | |
Concesionaria Tibitoc S.A. | | | 33 | % | | | 20,165 | | | | 33 | % | | | 20,209 | |
Metrex S.A. | | | 18 | % | | | 2,559 | | | | 18 | % | | | 2,239 | |
C.I. Acepalma S.A. (**) | | | 11 | % | | | 5,625 | | | | 11 | % | | | 4,367 | |
Gases del Caribe S.A. E.S.P. | | | 31 | % | | | 269,739 | | | | 31 | % | | | 218,432 | |
Gas Natural de Lima y Callao S.A. -Calidda S.A. | | | 40 | % | | | 363,139 | | | | 40 | % | | | 354,822 | |
Energía Eficiente S.A. | | | 39 | % | | | 6,927 | | | | 39 | % | | | 6,678 | |
Concentra Inteligencia en energía S.A.S | | | 24 | % | | | 603 | | | | 24 | % | | | 557 | |
| | | | | | | | | | | | | | | | |
| | | | | | Ps. | 925,823 | | | | | | | Ps. | 865,410 | |