UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

FORM 15

CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION

12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934.

Commission File Number: 001-7297

NICOR INC.

(predecessor company to OTTAWA ACQUISITION LLC)
(Exact name of registrant as specified in its charter)

1844 Ferry Road

Naperville, Illinois 60563-9600

(630) 305-9500

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Common Stock, par value $2.50 per share

(Title of each class of securities covered by this Form)

None

(Titles of all other classes of securities for which a duty to file reports under section 13(a) or 15(d) remains)

Please place an X in the box(es) to designate the appropriate rule provision(s) relied upon to terminate or suspend the duty to file reports:

Rule 12g-4(a)(1)	þ
Rule 12g-4(a)(2)	o
Rule 12h-3(b)(1)(i)	þ
Rule 12h-3(b)(1)(ii)	o
Rule 15d-6	o

Approximate number of holders of record as of the certification or notice date: 1

Pursuant to the requirements of the Securities Exchange Act of 1934, Ottawa Acquisition LLC, the successor company to NICOR Inc., has caused this certification/notice to be signed on its behalf by the undersigned duly authorized person.

Date: December 30, 2011

OTTAWA ACQUISITION LLC,

as successor company to NICOR Inc.

(Registrant)

By: /s/ Andrew W. Evans

Name: Andrew W. Evans

Executive Vice President, Chief Financial Officer and Manager

(Principal Financial and Accounting Officer)