Nicor Gas Company
                                                             Form 10-K
                                                             Exhibit 24.01


                              POWER OF ATTORNEY




KNOW ALL MEN BY THESE PRESENTS:

      That the  undersigned,  a Director,  Officer,  or Director  and Officer of
Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois
corporation,  does  hereby  constitute  and  appoint D. L.  CYRANOSKI  and M. T.
LORENZ,  and each of them,  the  undersigned's  true and  lawful  attorneys  and
agents,  each with full power and authority (acting alone and without the other)
to  execute  in the name and on  behalf  of the  undersigned  as such  Director,
Officer, or Director and Officer,  the 1999 Annual Report on Form 10-K (and such
amendment or amendments  thereto as may be  necessary)  to be filed  pursuant to
Section 13 or 15(d) of the Securities  Exchange Act of 1934,  hereby granting to
such  attorneys and agents,  and each of them,  full power of  substitution  and
revocation in the premises;  and hereby  ratifying and  confirming all that such
attorneys  and agents,  or any of them,  may do or cause to be done by virtue of
these presents.

      IN WITNESS  WHEREOF,  I have  hereunto  signed this Power of Attorney this
20th day of January, 2000.





                             ROBERT M. BEAVERS, JR.
                             Robert M. Beavers, Jr.



<PAGE>


                              POWER OF ATTORNEY




KNOW ALL MEN BY THESE PRESENTS:

      That the  undersigned,  a Director,  Officer,  or Director  and Officer of
Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois
corporation,  does  hereby  constitute  and  appoint D. L.  CYRANOSKI  and M. T.
LORENZ,  and each of them,  the  undersigned's  true and  lawful  attorneys  and
agents,  each with full power and authority (acting alone and without the other)
to  execute  in the name and on  behalf  of the  undersigned  as such  Director,
Officer, or Director and Officer,  the 1999 Annual Report on Form 10-K (and such
amendment or amendments  thereto as may be  necessary)  to be filed  pursuant to
Section 13 or 15(d) of the Securities  Exchange Act of 1934,  hereby granting to
such  attorneys and agents,  and each of them,  full power of  substitution  and
revocation in the premises;  and hereby  ratifying and  confirming all that such
attorneys  and agents,  or any of them,  may do or cause to be done by virtue of
these presents.

      IN WITNESS  WHEREOF,  I have  hereunto  signed this Power of Attorney this
20th day of January, 2000.





                                           BRUCE P. BICKNER
                                           Bruce P. Bickner



<PAGE>


                              POWER OF ATTORNEY




KNOW ALL MEN BY THESE PRESENTS:

      That the  undersigned,  a Director,  Officer,  or Director  and Officer of
Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois
corporation,  does  hereby  constitute  and  appoint D. L.  CYRANOSKI  and M. T.
LORENZ,  and each of them,  the  undersigned's  true and  lawful  attorneys  and
agents,  each with full power and authority (acting alone and without the other)
to  execute  in the name and on  behalf  of the  undersigned  as such  Director,
Officer, or Director and Officer,  the 1999 Annual Report on Form 10-K (and such
amendment or amendments  thereto as may be  necessary)  to be filed  pursuant to
Section 13 or 15(d) of the Securities  Exchange Act of 1934,  hereby granting to
such  attorneys and agents,  and each of them,  full power of  substitution  and
revocation in the premises;  and hereby  ratifying and  confirming all that such
attorneys  and agents,  or any of them,  may do or cause to be done by virtue of
these presents.

      IN WITNESS  WHEREOF,  I have  hereunto  signed this Power of Attorney this
20th day of January, 2000.





                              JOHN H. BIRDSALL, III
                              John H. Birdsall, III



<PAGE>


                              POWER OF ATTORNEY




KNOW ALL MEN BY THESE PRESENTS:

      That the  undersigned,  a Director,  Officer,  or Director  and Officer of
Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois
corporation,  does  hereby  constitute  and  appoint D. L.  CYRANOSKI  and M. T.
LORENZ,  and each of them,  the  undersigned's  true and  lawful  attorneys  and
agents,  each with full power and authority (acting alone and without the other)
to  execute  in the name and on  behalf  of the  undersigned  as such  Director,
Officer, or Director and Officer,  the 1999 Annual Report on Form 10-K (and such
amendment or amendments  thereto as may be  necessary)  to be filed  pursuant to
Section 13 or 15(d) of the Securities  Exchange Act of 1934,  hereby granting to
such  attorneys and agents,  and each of them,  full power of  substitution  and
revocation in the premises;  and hereby  ratifying and  confirming all that such
attorneys  and agents,  or any of them,  may do or cause to be done by virtue of
these presents.

      IN WITNESS  WHEREOF,  I have  hereunto  signed this Power of Attorney this
20th day of January, 2000.





                                           THOMAS A. DONAHOE
                                           Thomas A. Donahoe



<PAGE>


                              POWER OF ATTORNEY





KNOW ALL MEN BY THESE PRESENTS:

      That the  undersigned,  a Director,  Officer,  or Director  and Officer of
Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois
corporation,  does  hereby  constitute  and  appoint D. L.  CYRANOSKI  and M. T.
LORENZ,  and each of them,  the  undersigned's  true and  lawful  attorneys  and
agents,  each with full power and authority (acting alone and without the other)
to  execute  in the name and on  behalf  of the  undersigned  as such  Director,
Officer, or Director and Officer,  the 1999 Annual Report on Form 10-K (and such
amendment or amendments  thereto as may be  necessary)  to be filed  pursuant to
Section 13 or 15(d) of the Securities  Exchange Act of 1934,  hereby granting to
such  attorneys and agents,  and each of them,  full power of  substitution  and
revocation in the premises;  and hereby  ratifying and  confirming all that such
attorneys  and agents,  or any of them,  may do or cause to be done by virtue of
these presents.

      IN WITNESS  WHEREOF,  I have  hereunto  signed this Power of Attorney this
20th day of January, 2000.





                                           DENNIS J. KELLER
                                           Dennis J. Keller



<PAGE>


                              POWER OF ATTORNEY




KNOW ALL MEN BY THESE PRESENTS:

      That the  undersigned,  a Director,  Officer,  or Director  and Officer of
Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois
corporation,  does  hereby  constitute  and  appoint D. L.  CYRANOSKI  and M. T.
LORENZ,  and each of them,  the  undersigned's  true and  lawful  attorneys  and
agents,  each with full power and authority (acting alone and without the other)
to  execute  in the name and on  behalf  of the  undersigned  as such  Director,
Officer, or Director and Officer,  the 1999 Annual Report on Form 10-K (and such
amendment or amendments  thereto as may be  necessary)  to be filed  pursuant to
Section 13 or 15(d) of the Securities  Exchange Act of 1934,  hereby granting to
such  attorneys and agents,  and each of them,  full power of  substitution  and
revocation in the premises;  and hereby  ratifying and  confirming all that such
attorneys  and agents,  or any of them,  may do or cause to be done by virtue of
these presents.

      IN WITNESS  WHEREOF,  I have  hereunto  signed this Power of Attorney this
20th day of January, 2000.





                                           CHARLES S. LOCKE
                                           Charles S. Locke



<PAGE>


                              POWER OF ATTORNEY




KNOW ALL MEN BY THESE PRESENTS:

      That the  undersigned,  a Director,  Officer,  or Director  and Officer of
Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois
corporation,  does  hereby  constitute  and  appoint D. L.  CYRANOSKI  and M. T.
LORENZ,  and each of them,  the  undersigned's  true and  lawful  attorneys  and
agents,  each with full power and authority (acting alone and without the other)
to  execute  in the name and on  behalf  of the  undersigned  as such  Director,
Officer, or Director and Officer,  the 1999 Annual Report on Form 10-K (and such
amendment or amendments  thereto as may be  necessary)  to be filed  pursuant to
Section 13 or 15(d) of the Securities  Exchange Act of 1934,  hereby granting to
such  attorneys and agents,  and each of them,  full power of  substitution  and
revocation in the premises;  and hereby  ratifying and  confirming all that such
attorneys  and agents,  or any of them,  may do or cause to be done by virtue of
these presents.

      IN WITNESS  WHEREOF,  I have  hereunto  signed this Power of Attorney this
20th day of January, 2000.





                                           WILLIAM A. OSBORN
                                           William A. Osborn


<PAGE>


                              POWER OF ATTORNEY




KNOW ALL MEN BY THESE PRESENTS:

      That the  undersigned,  a Director,  Officer,  or Director  and Officer of
Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois
corporation,  does  hereby  constitute  and  appoint D. L.  CYRANOSKI  and M. T.
LORENZ,  and each of them,  the  undersigned's  true and  lawful  attorneys  and
agents,  each with full power and authority (acting alone and without the other)
to  execute  in the name and on  behalf  of the  undersigned  as such  Director,
Officer, or Director and Officer,  the 1999 Annual Report on Form 10-K (and such
amendment or amendments  thereto as may be  necessary)  to be filed  pursuant to
Section 13 or 15(d) of the Securities  Exchange Act of 1934,  hereby granting to
such  attorneys and agents,  and each of them,  full power of  substitution  and
revocation in the premises;  and hereby  ratifying and  confirming all that such
attorneys  and agents,  or any of them,  may do or cause to be done by virtue of
these presents.

      IN WITNESS  WHEREOF,  I have  hereunto  signed this Power of Attorney this
20th day of January, 2000.





                                          SIDNEY R. PETERSEN
                                          Sidney R. Petersen



<PAGE>


                              POWER OF ATTORNEY




KNOW ALL MEN BY THESE PRESENTS:

      That the  undersigned,  a Director,  Officer,  or Director  and Officer of
Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois
corporation,  does  hereby  constitute  and  appoint D. L.  CYRANOSKI  and M. T.
LORENZ,  and each of them,  the  undersigned's  true and  lawful  attorneys  and
agents,  each with full power and authority (acting alone and without the other)
to  execute  in the name and on  behalf  of the  undersigned  as such  Director,
Officer, or Director and Officer,  the 1999 Annual Report on Form 10-K (and such
amendment or amendments  thereto as may be  necessary)  to be filed  pursuant to
Section 13 or 15(d) of the Securities  Exchange Act of 1934,  hereby granting to
such  attorneys and agents,  and each of them,  full power of  substitution  and
revocation in the premises;  and hereby  ratifying and  confirming all that such
attorneys  and agents,  or any of them,  may do or cause to be done by virtue of
these presents.

      IN WITNESS  WHEREOF,  I have  hereunto  signed this Power of Attorney this
20th day of January, 2000.





                                               JOHN RAU
                                               John Rau



<PAGE>


                              POWER OF ATTORNEY




KNOW ALL MEN BY THESE PRESENTS:

      That the  undersigned,  a Director,  Officer,  or Director  and Officer of
Northern Illinois Gas Company (doing business as Nicor Gas Company), an Illinois
corporation,  does  hereby  constitute  and  appoint D. L.  CYRANOSKI  and M. T.
LORENZ,  and each of them,  the  undersigned's  true and  lawful  attorneys  and
agents,  each with full power and authority (acting alone and without the other)
to  execute  in the name and on  behalf  of the  undersigned  as such  Director,
Officer, or Director and Officer,  the 1999 Annual Report on Form 10-K (and such
amendment or amendments  thereto as may be  necessary)  to be filed  pursuant to
Section 13 or 15(d) of the Securities  Exchange Act of 1934,  hereby granting to
such  attorneys and agents,  and each of them,  full power of  substitution  and
revocation in the premises;  and hereby  ratifying and  confirming all that such
attorneys  and agents,  or any of them,  may do or cause to be done by virtue of
these presents.

      IN WITNESS  WHEREOF,  I have  hereunto  signed this Power of Attorney this
20th day of January, 2000.





                                           PATRICIA A. WIER
                                           Patricia A. Wier