|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|--------------------------------------------------------------------------------------------------------|--------|--------|--------|--------|---------------------------------------------|-------------|--------|--------|---------|--------|--------|---------|--------|--------|---------|--------|--------|---------|--------|
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
| **Nicor                Gas Company**                                                              |
| **Computation                of Consolidated Ratio of Earnings to Fixed                Charges**  |
| (thousands)                                                                                       |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|                                                                                                   |   |   |   |   |  Year                Ended December 31 |
|                                                                                                   |   |   |   |   |                                        | **2005**    |   |   | 2004    |   |   | 2003    |   |   | 2002    |   |   | 2001    |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
| Earnings                available to cover fixed charges:                                         |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|  Net                income                                                                        |   |   |   |   | **$**                                       | **53,476**  |   | $      | 62,106  |   | $      | 83,000  |   | $      | 109,139 |   | $      | 98,806  |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|  Add:                 Income tax expense                                                     |   |   |   |   |                                        | **26,128**  |   |   | 33,108  |   |   | 48,035  |   |   | 64,325  |   |   | 57,000  |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
| Fixed                charges                                                                           |   |   |   |   |                                        | **43,203**  |   |   | 37,555  |   |   | 37,047  |   |   | 36,711  |   |   | 45,431  |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
| Allowance                for funds                                                                     |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
| used                during construction and other                                                      |   |   |   |   |                                        | **(1,038**  | **)**  |   | (363    | )      |   | (220    | )      |   | (395    | )      |   | (241    | )      |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|                                                                                                   |   |   |   |   | **$**                                       | **121,769** |   | $      | 132,406 |   | $      | 167,862 |   | $      | 209,780 |   | $      | 200,996 |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
| Fixed                charges:                                                                     |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|  Interest                on debt                                                                  |   |   |   |   | **$**                                       | **36,487**  |   | $      | 35,606  |   | $      | 33,934  |   | $      | 33,037  |   | $      | 43,542  |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|  Other                interest charges and                                                        |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|  amortization                of debt discount,                                                    |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|  premium,                and expense, net                                                         |   |   |   |   |                                        | **6,716**   |   |   | 1,949   |   |   | 3,113   |   |   | 3,674   |   |   | 1,889   |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|                                                                                                   |   |   |   |   | **$**                                       | **43,203**  |   | $      | 37,555  |   | $      | 37,047  |   | $      | 36,711  |   | $      | 45,431  |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
|                                                                                                   |   |   |   |   |                                        |        |   |   |    |   |   |    |   |   |    |   |   |    |   |
| Ratio                of earnings to fixed charges                                                 |   |   |   |   |                                        | **2.82**    |   |   | 3.53    |   |   | 4.53    |   |   | 5.71    |   |   | 4.42    |   |