UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No. 1)*

TransAlta Corporation

(Name of Issuer)

Common Shares, No Par Value

(Title of Class of Securities)

89346D107

(CUSIP Number)

James J. Moloney

Gibson, Dunn & Crutcher LLP

3161 Michelson Drive

Irvine, CA 92612

(949) 451-4343

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

December 31, 2015

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

¨ Rule 13d-1(b)

x Rule 13d-1(c)

¨ Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 89346D107

1.	Names of Reporting Persons I.R.S. Identification No. of Above Persons (Entities Only) LUMINUS MANAGEMENT, LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  x        (b)  ¨
3.	SEC Use Only
4.	Citizenship or Place of Organization DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With	5.	Sole Voting Power 0
	6.	Shared Voting Power 20,150,849
	7.	Sole Dispositive Power 0
	8.	Shared Dispositive Power 20,150,849

9.	Aggregate Amount Beneficially Owned by Each Reporting Person 20,150,849
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  ¨
11.	Percent of Class Represented by Amount in Row (9) 7.1%
12.	Type of Reporting Person (See Instructions) IA

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CUSIP No. 89346D107

1.	Names of Reporting Persons I.R.S. Identification No. of Above Persons (Entities Only) LUMINUS ENERGY PARTNERS MASTER FUND, LTD.
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  x        (b)  ¨
3.	SEC Use Only
4.	Citizenship or Place of Organization BERMUDA
Number of Shares Beneficially Owned by Each Reporting Person With		5.	Sole Voting Power 0
		6.	Shared Voting Power 20,150,849
		7.	Sole Dispositive Power 0
		8.	Shared Dispositive Power 20,150,849
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 20,150,849
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  ¨
11.	Percent of Class Represented by Amount in Row (9) 7.1%
12.	Type of Reporting Person (See Instructions) OO

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CUSIP No. 89346D107

1.	Names of Reporting Persons I.R.S. Identification No. of Above Persons (Entities Only) VEGA ENERGY GP, LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  x        (b)  ¨
3.	SEC Use Only
4.	Citizenship or Place of Organization DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With		5.	Sole Voting Power 0
		6.	Shared Voting Power 20,150,849
		7.	Sole Dispositive Power 0
		8.	Shared Dispositive Power 20,150,849
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 20,150,849
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  ¨
11.	Percent of Class Represented by Amount in Row (9) 7.1%
12.	Type of Reporting Person (See Instructions) OO

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CUSIP No. 89346D107

1.	Names of Reporting Persons I.R.S. Identification No. of Above Persons (Entities Only) VEGA ASSET PARTNERS LP
2.	Check the Appropriate Box if a Member of a Group (See Instructions) (a)  x        (b)  ¨
3.	SEC Use Only
4.	Citizenship or Place of Organization DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With		5.	Sole Voting Power 0
		6.	Shared Voting Power 20,150,849
		7.	Sole Dispositive Power 0
		8.	Shared Dispositive Power 20,150,849
9.	Aggregate Amount Beneficially Owned by Each Reporting Person 20,150,849
10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  ¨
11.	Percent of Class Represented by Amount in Row (9) 7.1%
12.	Type of Reporting Person (See Instructions) PN

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Item 1.

(a) Name of Issuer

TransAlta Corporation

(b) Address of Issuer’s Principal Executive Offices

110 – 12th Avenue S.W., Box 1900, Station “M”, Calgary, Alberta, T2P 2M1

Item 2.

(a) Name of Person(s) Filing:

(A) LUMINUS MANAGEMENT, LLC

Luminus Management, LLC is the investment adviser of Luminus Energy Partners Master Fund, Ltd.

(B) LUMINUS ENERGY PARTNERS MASTER FUND, LTD.

(C) VEGA ENERGY GP, LLC

Vega Energy GP, LLC is the general partner of Vega Asset Partners LP

(D) VEGA ASSET PARTNERS LP

(b) Address of Principal Business Office or, if none, Residence:

(A) 1700 Broadway, 38th Floor, New York, NY 10019

(B) 1700 Broadway, 38th Floor, New York, NY 10019

(C) 1700 Broadway, 38th Floor, New York, NY 10019

(D) 1700 Broadway, 38th Floor, New York, NY 10019

(c) Citizenship:

(A) DELAWARE

(B) BERMUDA

(C) DELAWARE

(D) DELAWARE

(d) Title of Class of Securities: Common Shares, No Par Value

(e) CUSIP Number: 89346D107

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Item 3. If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

Not applicable

(a)	¨	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	¨	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	¨	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	¨	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	¨	An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E);
(f)	¨	An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F);
(g)	¨	A parent holding company or control person in accordance with §240.13d-1(b)(1)(ii)(G);
(h)	¨	A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	¨	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	¨	A non-U.S. institution in accordance with §240.13d-1(b)(1)(ii)(J);
(k)	¨	Group, in accordance with §240.13d-1(b)(1)(ii)(K). If filing as a non-U.S. institution in accordance with §240.13d-1(b)(1)(ii)(J), please specify the type of institution: .

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Item 4. Ownership

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

(a), (b), and (c)

Reporting Persons*	Number of Shares With Sole Voting and Dispositive Power		Number of Shares With Shared Voting and Dispositive Power		Aggregate Number of Shares Beneficially Owned		Percentage of Class Beneficially Owned**
LUMINUS MANAGEMENT, LLC		0		20,150,849		20,150,849		7.1	%
LUMINUS ENERGY PARTNERS MASTER FUND, LTD.		0		20,150,849		20,150,849		7.1	%
VEGA ENERGY GP, LLC		0		20,150,849		20,150,849		7.1	%
VEGA ASSET PARTNERS LP		0		20,150,849		20,150,849		7.1	%

* The above figures reflect the most recent beneficial ownership for each of the Reporting Persons above as of December 31, 2015.

** The Percentage of Class Beneficially Owned is based on 284,100,000 shares outstanding as of October 29, 2015, as reported by the Issuer in its third quarter 2015 earnings release.

Item 5. Ownership of Five Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following  ¨.

Item 6. Ownership of More than Five Percent on Behalf of Another Person

Not applicable.

Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person

Not applicable.

Item 8. Identification and Classification of Members of the Group

Given the relationship between each of the Reporting Persons on this Schedule 13G, such persons may be deemed members of a group pursuant to Rule 13d-5 under the Securities Exchange Act of 1934.

Item 9. Notice of Dissolution of Group

Not applicable.

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Item 10. Certification

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

Signature

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: February 16, 2016

Luminus Management, LLC
By:	/s/ Jonathan Barrett
Name:	Jonathan Barrett
Title:	President
Luminus Energy Partners Master Fund, Ltd.
By:	Luminus Management, LLC
Its:	Investment Manager
By:	/s/ Jonathan Barrett
Name:	Jonathan Barrett
Title:	President
Vega Energy GP, LLC
By:	/s/ Paul Segal
Name:	Paul Segal
Title:	President
Vega Asset Partners, LP
By:	Vega Energy GP, LLC
Its:	General Partner
By:	/s/ Paul Segal
Name:	Paul Segal
Title:	President

INDEX OF EXHIBITS

Exhibit No.	Description
A	Joint Filing Agreement dated September 21, 2015 (incorporated by reference to Exhibit A to the Schedule 13G filed with the Securities and Exchange Commission by the Reporting Persons on September 21, 2015).
B	Power of Attorney dated September 21, 2015 (incorporated by reference to Exhibit B to the Schedule 13G filed with the Securities and Exchange Commission by the Reporting Persons on September 21, 2015).