4.
Operating expenses
4.1. Raw materials and consumables used
| Year ended Dec 31 2014 | Year ended Dec 31 2013 | |
|---|---|---|
| Cost of gas sold | (18,750) | (17,569) |
| Fuels for electricity and heat generation | (760) | (908) |
| Electricity for trading | (1,093) | (670) |
| Other raw materials and consumables used | (626) | (726) |
| Total | (21,229) | (19,873) |
4.2. Employee benefits expense
| Year ended Dec 31 2014 | Year ended Dec 31 2013 | |
|---|---|---|
| Salaries and wages | (2,091) | (2,127) |
| Social security contributions | (460) | (484) |
| Cost of future employee benefits | 31 | (355) |
| Other employee benefits expense | (307) | (248) |
| Total | (2,827) | (3,214) |
4.3. Services
| Year ended Dec 31 2014 | Year ended Dec 31 2013 | |
|---|---|---|
| Transmission services | (1,076) | (1,113) |
| Cost of dry wells written off | (282) | (132) |
| Other services | (1,485) | (1,563) |
| Total | (2,843) | (2,808) |
4.4. Other income and expenses
| Year ended Dec 31 2014 | Year ended Dec 31 2013 | |
|---|---|---|
| Compensations, penalties, fines received | 50 | 187 |
| Other income | 169 | 160 |
| Net exchange differences related to operating activities | (59) | (351) |
| Net gain/(loss) on derivative instruments related to operating activities | (79) | 168 |
| Change in products | 40 | 22 |
| Change in impairment losses* | (863) | (491) |
| Increase/(decrease) in provisions | (319) | (211) |
| Taxes and charges | (606) | (574) |
| Other expenses | (373) | (430) |
| Total | (2,040) | (1,520) |
| * Including changes in impairment losses on tangible assets under construction related to the exploration for and evaluation of mineral resources. | (238) | (438) |