SEC FORM 13F-HR

The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F COVER PAGE

OMB APPROVAL
OMB Number: 3235-0006
Expires: July 31, 2015
Estimated average burden
hours per response: 23.8

Report for the Calendar Year or Quarter Ended: 03-31-2018
Check here if Amendment    Amendment Number:
This Amendment (Check only one.):    is a restatement.
   adds new holdings entries.
Institutional Investment Manager Filing this Report:
Name: STEEL PARTNERS HOLDINGS L.P.
Address: 590 MADISON AVENUE, 32ND FLOOR
NEW YORK, NY  10022
Form 13F File Number: 028-14001

The institutional investment manager filing this report and the person by whom it is signed hereby represent that the person signing the report is authorized to submit it, that all information contained herein is true, correct and complete, and that it is understood that all required items, statements, schedules, lists, and tables, are considered integral parts of this form.

Person Signing this Report on Behalf of Reporting Manager:
Name: Jack L. Howard
Title: President of General Partner of Reporting Manager
Phone: 212-520-2300
Signature, Place, and Date of Signing:
/s/ Jack L. Howard New YorkNY 05-11-2018
[Signature] [City, State] [Date]
Report Type (Check only one.):
X 13F HOLDINGS REPORT. (Check here if all holdings of this reporting manager are reported in this report.)
   13F NOTICE. (Check here if no holdings reported are in this report, and all holdings are reported by other reporting manager(s).)
   13F COMBINATION REPORT. (Check here if a portion of the holdings for this reporting manager are reported in this report and a portion are reported by other reporting manager(s).)
Form 13F Summary Page
Report Summary:
Number of Other Included Managers: 3
Form 13F Information Table Entry Total: 8
Form 13F Information Table Value Total: 229,918
(thousands)
List of Other Included Managers:
Provide a numbered list of the name(s) and Form 13F file number(s) of all institutional investment managers with respect to which this report is filed, other than the manager filing this report.
[If there are no entries in this list, state “NONE” and omit the column headings and list entries.]
No. Form 13F File Number Name
1 028-14563 SPH Group Holdings LLC
2 028-14887 SPH Group LLC
3 028-14886 Steel Partners Holdings GP Inc.

SEC FORM 13-F Information Table

The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE

OMB APPROVAL
OMB Number: 3235-0006
Expires: July 31, 2015
Estimated average burden
hours per response: 23.8

COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
AEROJET ROCKETDYNE HLDGS INC COM 007800105 116,942 4,180,997 SH   OTR 1, 2, 3 0 4,180,997 0
AVIAT NETWORKS INC COM NEW 05366Y201 11,233 670,240 SH   OTR 1, 2, 3 0 670,240 0
BABCOCK & WILCOX ENTERPRIS I COM 05614L100 30,560 6,993,219 SH   OTR 1, 2, 3 0 6,993,219 0
ESTERLINE TECHNOLOGIES CORP COM 297425100 732 10,000 SH   OTR 1, 2, 3 0 10,000 0
HUGOTON RTY TR TEX UNIT BEN INT 444717102 700 1,000,000 SH   OTR 1, 2, 3 0 1,000,000 0
STEEL CONNECT INC COM 858098106 38,547 18,182,705 SH   OTR 1, 2, 3 0 18,182,705 0
MODUSLINK GLOBAL SOLUTIONS I NOTE 5.250% 3/0 60786LAB3 14,431 14,940,000 PRN   OTR 1, 2, 3 0 14,940,000 0
STEEL PARTNERS HLDGS L P LTD PRTRSHIP U 85814R107 16,772 936,968 SH   OTR 1, 2, 3 0 936,968 0