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|   | o      | REGISTRATION STATEMENT PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934    |
|--------|--------|-----------------------------------------------------------------------------------------|
|   |   | OR                                                                                      |   |
|   | x      | ANNUAL REPORT PURSUANT TO SECTION 13(a) OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 |

| For the fiscal year ended | December 31, 2011 | Commission File Number          | 000-30514 |
|---------------------------|------------------------|------------------------------------------------------------------------------|-----------|
|                      |                   |                                                                         |      |

| ARC RESOURCES LTD.                                     |
|--------------------------------------------------------|
| (Exact name of Registrant as specified in its charter) |

| N/A                                                                                                      |
|----------------------------------------------------------------------------------------------------------|
| (Translation of Registrant’s name into English (if applicable))                                    |
|                                                                                                     |
| ALBERTA                                                                                                  |
| (Province or other jurisdiction of incorporation or organization)                                        |
|                                                                                                     |
| 1311                                                                                                     |
| (Primary Standard Industrial Classification Code Number (if applicable))                                 |
|                                                                                                     |
| N/A                                                                                                      |
| (I.R.S. Employer Identification Number (if applicable))                                                  |
|                                                                                                     |
| 1200, 308 4th Avenue S.W., Calgary, Alberta, Canada T2P 0H7 (403) 503-8600                               |
| (Address and telephone number of Registrant’s principal executive offices)                         |
|                                                                                                     |
| Corporation Service Company, 2711 Centerville Road, Suite 400, Wilmington, Delaware 19805 (302) 636-5401 |
| (Name, address (including zip code) and telephone number (including area code)                           |
| of agent for service in the United States)                                                               |

| Title of each class |   | Name of each exchange on which registered |
|---------------------|--------|-------------------------------------------|
| N/A                 | N/A    |

| COMMON SHARES    |
|------------------|
| (Title of Class) |

| N/A              |
|------------------|
| (Title of Class) |

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|   | A. | Undertaking |
|--------|----|-------------|

|   | B. | Consent to Service of Process |
|--------|----|-------------------------------|

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| ARC RESOURCES LTD. |
|--------------------|
| (the Registrant)   |
|               |
| By:                | /s/ John P. Dielwart |
|               | John P. Dielwart |
|               | Chief Executive Officer |
|               |   |
| Date:              | September 12, 2012 |

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| Exhibit Number | Description                                                                                                                                                       |
|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|           |                                                                                                                                                              |
|  99.1*    | Annual Information Form for the fiscal year ended December 31, 2011.                                                                                         |
|           |                                                                                                                                                              |
| 99.2           | Consolidated Financial Statements for the fiscal year ended December 31, 2011.                                                                               |
|           |                                                                                                                                                              |
| 99.3           | Management’s Discussion and Analysis for the fiscal year ended December 31, 2011.                                                                      |
|           |                                                                                                                                                              |
| 99.4           | Certification of Chief Executive Officer pursuant to Rule 13a-14(a) or 15d-14(a) of the Securities Exchange Act of 1934.                                          |
|           |                                                                                                                                                              |
| 99.5           | Certification of Chief Financial Officer pursuant to Rule 13a-14(a) or 15d-14(a) of the Securities Exchange Act of 1934.                                          |
|           |                                                                                                                                                              |
| 99.6           | Certification of Chief Executive Officer pursuant to Rule 13(a)-14(b) and Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. 1350).      |
|           |                                                                                                                                                              |
| 99.7           | Certification of Chief Financial Officer pursuant to Rule 13(a)-14(b) and Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. 1350).      |
|           |                                                                                                                                                              |
| 99.8           | Consent of Deloitte & Touche LLP, Independent Registered Chartered Accountants.                                                                               |
|           |                                                                                                                                                              |
|  99.9*    | Consent of GLJ Petroleum Consultants Ltd. to the inclusion of the Report dated February 15, 2012 evaluating the reserves and resources of ARC Resources Ltd. |

|   | *    Previously filed with the Registrant’s Original Form 40-F as filed with the Securities and Exchange Commission on March 27, 2012. |
|--------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|

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