U.S. SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

SCHEDULE 13G/A

Under the Securities Exchange Act of 1934

(Amendment No. 2)

Horizon Lines, Inc.

(Name of Issuer)

Class A Common Stock

(Title of Class of Securities)

44044K101

(CUSIP Number)

December 31, 2010

Date of Event Which Requires Filing of this Statement

Check the appropriate box to designate the rule

pursuant to which this Schedule is filed

[X] Rule 13d-1(b)

[ ] Rule 13d-1(c)

[ ] Rule 13d-1(d)

1) Name of Reporting Person: Pioneer Global Asset Management S.p.A. (PGAM)

2) Check the Appropriate Box (a)

of A Member of Group

(See Instructions) (b)

3) SEC Use Only

4) Citizenship of Place of

Organization Italy

Number of (5) Sole Voting

Shares Power 0

Beneficially Owned

by Each Reporting

Person With (6) Shared Voting

Power 1,820,494

[See Item 4 below.]

(7) Sole Disposi-

tive Power 0

(8) Shared Disposi-

tive Power 1,820,494

[See Item 4 below.]

9) Aggregate Amount Beneficially 1,820,494

Owned by Each [See Item 4 below.]

Reporting Person

10) Check if the aggregate Amount in Row (9) Exclude Certain Shares (See

Instructions)

11) Percent of Class Represented

By Amount in Row 9. 5.6%

12) Type of Reporting

Person (See Instructions) FI

1) Name of Reporting Person: Pioneer Investment Management, Inc. (PIM)

2) Check the Appropriate Box (a)

of A Member of Group

(See Instructions) (b)

3) SEC Use Only

4) Citizenship of Place of

Organization Delaware

Number of (5) Sole Voting

Shares Power 0

Beneficially Owned

by Each Reporting

Person With (6) Shared Voting

Power 1,504,828

[See Item 4 below.]

(7) Sole Disposi-

tive Power 0

(8) Shared Disposi-

tive Power 1,504,828

[See Item 4 below.]

9) Aggregate Amount Beneficially 1,504,828

Owned by Each [See Item 4 below.]

Reporting Person

10) Check if the aggregate Amount in Row (9) Exclude Certain Shares (See

Instructions)

11) Percent of Class Represented

By Amount in Row 9. 4.6%

12) Type of Reporting

Person (See Instructions) IA

Item 1(a) Name of Issuer.

Horizon Lines, Inc.

Item 1(b) Address of Issuer's Principal Executive Offices:

4064 Colony Road

Suite 200

Charlotte, NC 28211

United States

Item 2(a) Name of Person Filing:

PGAM and PIM

Item 2(b) Address of Principal Business Office:

The principal business office for PGAM is:

Galleria San Carlo 6

Milan, Italy

The principal business office for PIM is:

60 State Street

Boston, MA 02109

Item 2(c) Citizenship:

PGAM is organized under the laws of Italy.

PIM is a corporation organized under the laws of the

State of Delaware.

Item 2(d) Title of Class of Securities:

Class A Common Stock

Item 2(e) Cusip Number:

44044K101

Item 3 The person filing this statement pursuant to Rule 13d-1(b)

or 13d-2(b) is:

PGAM is a parent holding company or control

person in accordance with Section 240.13d-1(b)(1)(ii)(J).

PIM is an investment adviser in accordance with Section

240.13d-1(b)(1)(ii)(E).

Item 4. Ownership.

(a) Amount Beneficially Owned:**

PGAM: 1,820,494

PIM: 1,504,828

(b) Percent of Class:

PGAM: 5.6%

PIM: 4.6%

(i) sole power to vote or to direct the vote: 0

(ii) shared power to vote or to direct vote: **

PGAM: 1,820,494

PIM: 1,504,828

(iii) sole power to dispose or to direct disposition of:0

(iv) shared power to dispose or to direct disposition:**

PGAM: 1,820,494

PIM: 1,504,828

**Shares reported on this Schedule 13G (the Shares) are owned by (i) collective

investment vehicles (Funds) advised by PIM and (ii) Funds advised by other

advisors that are direct or indirect wholly-owned subsidiaries of PGAM

(Additional PGAM Subsidiaries). In their roles as investment manager or adviser

to the Funds, PIM and the Additional PGAM Subsidiaries possess investment and/or

voting control over the Shares.

PIM is a direct subsidiary of PGAM. PGAM is a limited liability company and the

holding company incorporating all of the Pioneer Investments asset management

business (including PIM, and the Additional PGAM Subsidiaries) and may

therefore, be deemed to beneficially own the Shares.

PGAM, PIM, and the Additional PGAM Subsidiaries disclaim beneficial ownership of

the Shares except to the extent or their respective pecuniary interests therein,

if any. The filing of this Schedule 13G shall not be construed as an admission

that the Reporting Persons are the beneficial owners of the Shares for any other

purposes than Section 13(d) of the Securities Exchange Act of 1934.

In accordance with Securities and Exchange Commission Release No.34-39538

(January 12, 1998) (the"Release"), this filing reflects the securities that may

be deemed to be beneficially owned by the Reporting Persons, each of which is a

directly or indirectly owned subsidiary of Unicredit S.p.A. ("Unicredit"). This

filing does not reflect securities, if any, beneficially owned by Unicredit or

any other subsidiaries of Unicredit whose ownership is disaggregated from that

of the Reporting Persons in accordance with the 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 here:

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

Inapplicable.

Item 7. Identification and Classification of the Subsidiary Which Acquired

the Security Being Reported On By the Parent Holding Company.

See Item 4.

Item 8. Identification and Classification of Members of the Group.

Inapplicable.

Item 9. Notice of Dissolution of the Group.

Inapplicable.

Item 10. Certification.

By signing below I certify that, to the best of my knowledge and belief,

the securities referred to above were acquired and are held in the ordinary

course of business and 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.

By signing below PGAM certifies that to the best of its knowledge and

belief, the foreign regulatory scheme applicable to it as a sub-holding company

for the asset management division in the UniCredit Banking Group, the latter

being regulated by the Bank of Italy and the Commissione Nazionale per le

Societa`e la Borsa (CONSOB), is substantially comparable to the regulatory

scheme applicable to the functionally equivalent U.S. institution(s). PGAM also

undertakes to furnish to the Commission staff, upon request, information that

would otherwise be disclosed in a Schedule 13D.

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.

Date: February 1, 2011

Pioneer Global Asset Management S.p.A

By: /s/ Roger Yates

Name: Roger Yates

Title: CEO; Head of Asset Management Division

Pioneer Investment Management, Inc.

By: /s/ Jean M. Bradley

Name: Jean M. Bradley

Title: Chief Compliance Officer

EXHIBIT

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) promulgated under the Securities Exchange

Act of 1934, the undersigned agree to the joint filing of a Statement on

Schedule 13G (including any and all amendments thereto) with respect to the

Common Stock of Horizon Lines, Inc. and further agree to the filing of

this agreement as an Exhibit thereto. Each party to this Agreement expressly

authorizes each other party to this Agreement to file on its behalf any and all

amendments to such Statement on Schedule 13G.

Date: February 1, 2011

Pioneer Global Asset Management S.p.A

By: /s/ Roger Yates

Name: Roger Yates

Title: CEO; Head of Asset Management Division

Pioneer Investment Management, Inc.

By: /s/ Jean M. Bradley

Name: Jean M. Bradley

Title: Chief Compliance Officer

PIONEER GLOBAL ASSET MANAGEMENT SPA SC 13G/A