Exhibit 99.1

FORM OF INSTRUCTIONS

AS TO USE OF

STAR BULK CARRIERS CORP.

RIGHTS CERTIFICATES

CONSULT THE INFORMATION AGENT, YOUR BANK OR BROKER

AS TO ANY QUESTIONS

The following instructions relate to a rights offering (the "Rights Offering") by Star Bulk Carriers Corp., a Marshall Islands corporation ("Star Bulk"), to the holders of record (the "Recordholders") of its common shares, par value $0.01 per share (the "Common Shares"), as described in the Star Bulk prospectus dated [●], 2013 (the "Prospectus"). Recordholders of Common Shares as of 5:00 p.m., New York City time, on May 15, 2013 (the "Record Date") are receiving, at no charge, non-transferable subscription rights (the "Rights") to subscribe for and purchase Common Shares (the "Underlying Shares"). In the Rights Offering, Star Bulk is offering an aggregate of 14,018,692 Underlying Shares.

Each Recordholder will receive one Right for each Common Share owned of record as of 5:00 p.m., New York City time, on the Record Date. The Rights will expire, if not exercised prior to 5:00 p.m., New York City time, on [●], 2013, unless extended (the "Expiration Time"). Each Right allows the holder thereof to subscribe for 2.5957 Common Shares (the "Subscription Privilege") at the cash price of $5.35 per share (the "Subscription Price"). For example, if a Recordholder owned 100 Common Shares as of 5:00 p.m., New York City time on the Record Date, it would receive 100 Rights and would have the right to purchase 259.57 Common Shares (rounded down to 259 shares, with the total subscription payment being adjusted accordingly, as discussed below) for the Subscription Price.

Each Recordholder will be required to submit payment in full for all the Common Shares it wishes to purchase pursuant to its Subscription Privilege.

Fractional shares resulting from the exercise of the Subscription Privilege will be eliminated by rounding down to the nearest whole share, with the total exercise price being adjusted accordingly. Any excess subscription payments received by the Subscription Agent will be returned, without interest, as soon as practicable.

Star Bulk will not be required to issue Common Shares to you if the Subscription Agent does not receive your payment prior to the Expiration Time, regardless of when you send the subscription payment and related documents, unless you send the documents in compliance with the guaranteed delivery procedures described below. Star Bulk may extend the Expiration Time by giving oral or written notice to the Subscription Agent on or before the Expiration Time.  The Rights will be evidenced by non-transferable Rights certificates (the "Rights Certificates").

The number of Rights to which you are entitled is printed on the face of your Rights Certificate.  You should indicate your wishes with regard to the exercise of your Rights by completing the appropriate portions of your Rights Certificate and returning the certificate to the Subscription Agent in the envelope provided.

YOUR RIGHTS CERTIFICATES AND SUBSCRIPTION PRICE PAYMENT FOR EACH UNDERLYING SHARE, INCLUDING FINAL CLEARANCE OF ANY CHECKS, MUST BE RECEIVED BY THE SUBSCRIPTION AGENT, ON OR BEFORE THE EXPIRATION TIME. ONCE A HOLDER OF RIGHTS HAS EXERCISED THE SUBSCRIPTION PRIVILEGE, SUCH EXERCISE MAY NOT BE REVOKED. RIGHTS NOT EXERCISED PRIOR TO THE EXPIRATION TIME OF THE RIGHTS OFFERING WILL EXPIRE.

1.           Method of Subscription — Exercise of Rights.

To exercise Rights, complete your Rights Certificate and send the properly completed and executed Rights Certificate evidencing such Rights with any signatures required to be guaranteed so guaranteed, together with payment in full of the Subscription Price for each Underlying Share subscribed for pursuant to the Subscription Privilege to the Subscription Agent, on or prior to the Expiration Time. Payment of the Subscription Price will be held in a segregated account to be maintained by the Subscription Agent. All payments must be made in U.S. dollars for the full number of Underlying Shares being subscribed for (a) by certified or uncertified check or bank draft (cashier's check) drawn upon a U.S. bank or postal, telegraphic or express money order payable to American Stock Transfer and Trust Company, LLC, as Subscription Agent, or (b) by wire transfer of immediately available funds, to the account maintained by the Subscription Agent for purposes of accepting subscriptions in the Rights Offering at JP Morgan Chase Bank, ABA No. 021000021, further credit to Account Number 530-354624 (the "Subscription Account"). Any wire transfer should clearly indicate the identity of the subscriber who is paying the Subscription Price by wire transfer. Payments will be deemed to have been received upon (i) clearance of any uncertified check, (ii) receipt by the Subscription Agent of any certified check or bank draft drawn upon a U.S. bank or of any postal, telegraphic or express money order or (iii) receipt of collected funds in the Subscription Account designated above. If paying by uncertified personal check, please note that the funds paid thereby may take five or more business days to clear. Accordingly, Rights holders who wish to pay the Subscription Price by means of uncertified personal check are urged to make payment sufficiently in advance of the Expiration Time to ensure that such payment is received and clears by such date and are urged to consider payment by means of certified or cashier's check, money order or wire transfer of funds.

The Rights Certificate and payment of the Subscription Price must be delivered to the Subscription Agent by one of the methods described below:

By Mail: American Stock Transfer & Trust Company, LLC Operations Center Attn: Reorganization Department P. O. Box 2042 New York, New York 10272-2042	By Hand, Express mail, Courier, or Other Expedited Service: American Stock Transfer & Trust Company, LLC Operations Center Attn: Reorganization Department 6201 15th Avenue Brooklyn, New York 11219
Telephone Number for Confirmation: (718) 921-8317 Telephone Number for Information: (877) 870-5038 or if you are a bank or broker, (206) 870-8565 Information Agent, Advantage Proxy Inc.

Delivery to an address other than those above does not constitute valid delivery.

By making arrangements with your bank or broker for the delivery of funds on your behalf you may also request such bank or broker to exercise the Rights Certificate on your behalf.

If you do not indicate the number of Rights being exercised, or do not forward full payment of the Subscription Price, then you will be deemed to have exercised your Rights with respect to the maximum number of whole Rights that may be exercised with the aggregate Subscription Price you delivered to the Subscription Agent.  If we do not apply your full Subscription Price payment to your purchase of Underlying Shares, the excess subscription payment received by the Subscription Agent will be returned to you, without interest, as soon as practicable.

Brokers, custodian banks and other nominee holders of Rights who exercise the Subscription Privilege on behalf of beneficial owners of Rights will be required to certify to the Subscription Agent and Star Bulk as to the aggregate number of Rights that have been exercised pursuant to the Subscription Privilege by each beneficial owner of Rights (including such nominee itself) on whose behalf such nominee holder is acting.

2. Issuance of Common Shares.

The following deliveries and payments will be made to the address shown on the face of your Rights Certificate, unless you provide instructions to the contrary in your Rights Certificate.

(a)           Subscription Privilege. As soon as practicable after the Expiration Time and the valid exercise of Rights, the Subscription Agent will mail to each exercising Rights holder certificates representing the Underlying Shares purchased pursuant to the Subscription Privilege.

(b)           Excess Cash Payments. As soon as practicable after the Expiration Time and after all prorations and adjustments contemplated by the terms of the Rights Offering have been effected (if any), any excess subscription payments received in payment of the Subscription Price to the Subscription Agent will be mailed to each Rights holder, without interest.

3. Sale of Transfer of Rights.

The subscription rights granted to you are non-transferable and, therefore, you may not sell, transfer or assign your subscription rights to anyone.

4. Execution.

(a)           Execution by Registered Holder. The signature on the Rights Certificate must correspond with the name of the registered holder exactly as it appears on the face of the Rights Certificate without any alteration or change whatsoever. Persons who sign the Rights Certificate in a representative or other fiduciary capacity must indicate their capacity when signing and, unless waived by the Subscription Agent in its sole and absolute discretion, must present to the Subscription Agent satisfactory evidence of their authority to so act.

(b)           Execution by Person Other than Registered Holder. If the Rights Certificate is executed by a person other than the holder named on the face of the Rights Certificate, proper evidence of authority of the person executing the Rights Certificate must accompany the same unless, for good cause, the Subscription Agent dispenses with proof of authority.

(c)           Signature Guarantees. Your signature must be guaranteed by an Eligible Institution if you specify special payment or delivery instructions.

5. Method of Delivery.

The method of delivery of Rights Certificates and payment of the Subscription Price to the Subscription Agent will be at the election and risk of the Rights holder. However, if you elect to exercise your Rights, Star Bulk urges you to consider using a certified or cashier's check, money order, or wire transfer of funds to ensure that the Subscription Agent receives your funds prior to the Expiration Time. If you send an uncertified check, payment will not be deemed to have been received by the Subscription Agent until the check has cleared, but if you send a certified check, bank draft drawn upon a U.S. bank, a postal, telegraphic or express money order or wire or transfer funds directly to the Subscription Agent's account, payment will be deemed to have been received by the Subscription Agent immediately upon receipt of such instruments and wire or transfer. Any personal check used to pay for Underlying Shares must clear the appropriate financial institutions prior to the Expiration Time. The clearinghouse may require five or more business days. Accordingly, Recordholders that wish to pay the Subscription Price by means of an uncertified personal check are urged to make payment sufficiently in advance of the Expiration Time to ensure such payment is received and clears by such date.

6. Special Provisions Relating to the Delivery of Rights through the Depository Trust Company.

In the case of Rights that are held of record through The Depository Trust Company ("DTC"), exercises of the Subscription Privilege may be effected by instructing DTC to transfer Rights from the DTC account of such holder to the DTC account of the Subscription Agent, together with certification as to the aggregate number of Rights exercised subscribed for pursuant to the Subscription Privilege by each beneficial owner of Rights on whose behalf such nominee is acting, and payment of the Subscription Price for each Underlying Share subscribed for pursuant to the Subscription Privilege.

7. Substitute Form W-9.

TO ENSURE COMPLIANCE WITH IRS CIRCULAR 230, YOU ARE HEREBY NOTIFIED THAT: (A) ANY DISCUSSION OF U.S. FEDERAL TAX ISSUES CONTAINED OR REFERRED TO HEREIN IS NOT INTENDED OR WRITTEN TO BE USED, AND CANNOT BE USED BY ANY TAXPAYER FOR THE PURPOSE OF AVOIDING U.S. FEDERAL, STATE OR LOCAL TAX PENALTIES, (B) SUCH DISCUSSION IS WRITTEN IN CONNECTION WITH THE PROMOTION OR MARKETING OF THE TRANSACTION OR MATTERS DISCUSSED HEREIN, AND (C) THE TAXPAYER SHOULD SEEK ADVICE BASED ON THEIR PARTICULAR CIRCUMSTANCES FROM AN INDEPENDENT TAX ADVISOR.

Each Rights holder who elects to exercise Rights should provide the Subscription Agent with a correct Taxpayer Identification Number ("TIN") on Substitute Form W-9, a copy of which is included as Exhibit B hereto. Additional copies of Substitute Form W-9 may be obtained upon request from the Subscription Agent at the address set forth above or by calling Advantage Proxy Inc., the Information Agent, at (877) 870-5038 or if you are a bank or broker, (206) 870-8565. Failure to provide the information on the form may subject such holder to a $50.00 penalty for each such failure and to U.S. federal income tax backup withholding (currently at a 28% rate) with respect to dividends that may be paid by Star Bulk on Common Shares purchased upon the exercise of Rights (for those holders exercising Rights).

EXHIBIT B

Name
Business name, if different from above.
Check appropriate box:
	o	Individual/Sole Proprietor		o	Corporation	o	Partnership		o  Other
	o	Limited liability company. Enter the tax classification (D=disregard entity, C=corporation, P=partnership) ____
	o	Exempt Payee
Address (number, street, and apt, or suite no.)
City, State, and ZIP code
REQUESTER'S NAME
Give Form to the Requester.  Do NOT send to IRS
SUBSTITUTE FORM W-9			Part I – TAXPAYER IDENTIFICATION NUMBER (TIN). Enter your TIN in the appropriate box. For most individuals, this is your social security number (SSN).  For most other entities, it is your employer identification number (EIN). CERTIFY BY SIGNING AND DATING BELOW.							Social Security  Number __________________
			Note: If the account is in more than one name, see the chart in the enclosed Guidelines to determine which number to provide.							Employer Identification Number ________________
Department of the Treasury Internal Revenue Service										(If awaiting TIN, write "Applied For")
			Part II – If you are exempt from backup withholding, see the enclosed guidelines and complete as instructed.
Payer's Request
For Taxpayer			Part III – Certification
Identification Number			Under penalties of perjury, I certify that: (1)The number shown on this form is my correct TIN (or I am waiting for a number to be issued to me), (2)I am not subject to backup withholding because: (a) I am exempt from backup withholding; or (b) I have not been notified by the Internal Revenue Service (IRS) that I am subject to backup withholding as a result of a failure to report all interest or dividends; or (c) the IRS has notified me that I am no longer subject to backup withholding, and (3)I am a U.S. person (including a U.S. resident alien).
			CERTIFICATION INSTRUCTIONS – You must cross out item (2) above if you have been notified by the IRS that you are subject to backup withholding because you have failed to report all interest and dividends on your tax return.  However, if after being notified by the IRS that you were subject to backup withholding you received another notification from the IRS that you are no longer subject to backup withholding, do not cross out item (2). The IRS does not require your consent to any provision of this document other than the certifications required to avoid backup withholding.
			Signature					Date

YOU MUST COMPLETE THE FOLLOWING CERTIFICATION IF YOU WROTE

"APPLIED FOR" IN PART I OF THE SUBSTITUTE FORM W-9

CERTIFICATE OF AWAITING TAXPAYER IDENTIFICATION NUMBER
I certify under the penalties of perjury that a taxpayer identification number has not been issued to me, and either (a) I have mailed or delivered an application to receive a taxpayer identification number to the appropriate Internal Revenue Center or Social Security Administrative Office, or (b) I intend to mail or deliver an application in the near future.  I understand that if I do not provide a taxpayer identification number to the Subscription Agent, 28% of all reportable payments made to me will be withheld, but will be refunded to me if I provide a certified taxpayer identification number within 60 days.
Signature	Date:

NOTE: FAILURE TO COMPLETE AND RETURN THIS SUBSTITUTE FORM W-9 MAY RESULT IN BACKUP WITHHOLDING OF 28% OF ANY PAYMENTS OF DIVIDENDS MADE TO YOU. PLEASE REVIEW THE ENCLOSED GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION NUMBER ON SUBSTITUTE FORM W-9 FOR ADDITIONAL INFORMATION.

GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION NUMBER

ON SUBSTITUTE FORM W-9

GUIDELINES FOR DETERMINING THE PROPER IDENTIFICATION NUMBER TO GIVE THE PAYER. — Social Security numbers have nine digits separated by two hyphens, e.g. 000-00-0000. Employer identification numbers have nine digits separated by only on hyphen, e.g., 00-0000000. The table below will help determine the number to give the payer.

For this type of account:		Give the name* and SOCIAL SECURITY number of –
1.	An individual's account	The individual
2.	Two or more individuals (joint account)	The actual owner of the account or, if combined funds, the first individual on the account(1)
3.	Custodian account of a minor (Uniform Gift to Minors Act)	The minor(2)
4.	A revocable savings trust account (in which grantor is also trustee)	The grantor-trustee(1)
5.	Sole proprietorship or single owner LLC account	The owner(3)
For this type of account:		Give the name* an EMPLOYER IDENTIFICATION number of –
6.	A valid trust, estate, or pension trust	The legal entity (do not furnish the identifying number of the personal representative or trustee unless the legal entity itself is not designated in the account title)(4)
7.	Corporate (or LLC electing corporate status on Form 8832) account	The corporation
8.	Religious, charitable, or educational organization account	The organization
9.	Partnership account held in the name of the business	The partnership
10.	Association, club, or other tax-exempt organization	The organization
11.	A broker or registered nominee	The broker or nominee
12.	Account with Department of Agriculture in the name of a public entity (such as a State or local government, school district, or prison) that receives agricultural program payments	The public entity
*	If you are an individual, you must generally enter the name shown on your social security card. However, if you have changed your last name, for instance, due to marriage, without informing the Social Security Administration of the name change, enter your first name, the last name shown on your social security card, and your new last name.
(1)	List first and circle the name of the person whose number you furnish. If only one person on a joint account has a social security number, that person's number must be furnished.
(2)	Circle the minor's name and furnish the minor's social security number.
(3)	Show the individual name of the owner. If the owner does not have an employer identification number, furnish the owner's social security number.
(4)	List first and circle the name of the legal trust, estate or pension trust.
NOTE: If no name is circled when there is more than one name, the number will be considered to be that of the first name listed

Obtaining a Number

If you do not have a TIN or you do not know your TIN; obtain form SS-5, Application for a Social Security Number Card (for resident individuals), Form SS-4, Application for Employer Identification Number (for businesses and all other entities), Form W-7 Application for IRS Individual Taxpayer Identification Number (for alien individuals required to file U.S. tax returns). You may obtain Form SS-5 from your local Social Security Administration Office and Forms SS-4 and W-7 from the IRS by calling 1-800-TAX-FORM (1-800-829-3676) or from the IRS's Internet Web Site at www.irs.gov.

To complete the Substitute Form W-9, if you do not have a taxpayer identification number, write "Applied For" in the space for the TIN in Part 1.  Sign and date the Form, and give it to the Requester. Generally, you will then have 60 days to obtain a TIN and furnish it to the Requester. If the payer does not receive your TIN within 60 days, backup withholding, if applicable, will begin and will continue until you furnish your TIN to the Requestor. Note: Writing "Applied For" means that you have already applied for a TIN or that you intend to apply for one soon.

Payees Exempt from Backup Withholding

Payees specifically exempted from backup withholding on ALL payments include the following:*

· An organization exempt from tax under section 501(a), or an individual retirement plan, or a custodial account under section 403(b)(7) if the account satisfies the requirements of section 401(f)(2).

· The United States or any agency or instrumentality thereof.

· A State, the District of Columbia, a possession of the United States, or any political subdivision or instrumentality thereof.

· A foreign government or a political subdivision, agency or instrumentality thereof.

· An international organization or any agency or instrumentality thereof.

Payees that may be exempt from backup withholding include the following:

· A corporation;

· A foreign central bank of issue;

· A dealer in securities or commodities required to register in the United States, the District of Columbia or a possession of the United States;

· A futures commission merchant registered with the Commodity Futures Trading Commission;

· A real estate investment trust;

· An entity registered at all times during the tax year under the Investment Company Act of 1940;

· A common trust fund operated by a bank under section 584(a);

· A financial institution;

· A middleman known in the investment community as a nominee or custodian; or

· A trust exempt from tax under section 664 or described in section 4947.

Payments of dividends and patronage dividends not generally subject to backup withholding include the following:

· Payments to nonresident aliens subject to withholding under section 1441.

· Payments to partnerships not engaged in a trade or business in the United States and which have at least one nonresident alien partner.

· Payments of patronage dividends not paid in money.

· Payments made by certain foreign organizations.

· Section 404(k) distributions made by an ESOP.

Exempt payees described above should file a Substitute Form W-9 to avoid possible erroneous backup withholding. FILE THIS FORM WITH THE PAYER, FURNISH YOUR TAXPAYER IDENTIFICATION NUMBER, WRITE "EXEMPT" IN PART 2, SIGN AND DATE THE FORM AND RETURN IT TO THE PAYER.

Certain payments other than interest, dividends and patronage dividends that are not subject to information reporting are also not subject to backup withholding. For details, see sections 6041, 6041A, 6042, 6044, 6045, 6049, 6050A and 6050N and their regulations.

Privacy Act Notices. Section 6109 requires you to give your correct TIN to persons who must file information returns with the IRS to report interest, dividends and certain other payments. The IRS uses the numbers for identification purposes and to help verify the accuracy of your tax return. The IRS also may provide this information to the Department of Justice for civil and criminal litigation, and to cities, states and the District of Columbia to carry out their tax laws.

You must provide your TIN to the payer whether or not you are required to file a tax return. Payers must generally withhold 28% of taxable interest, dividends, and certain other payments to a payee who does not give a TIN to a payer. Certain penalties also may apply.

Penalties

(1)           Penalty for Failure to Furnish TIN. If you fail to furnish your TIN to a payer, you are subject to a penalty of $50 for each such failure unless your failure is due to reasonable cause and not to willful neglect.

(2)           Civil Penalty for False Statements With Respect to Withholding. If you make a false statement with no reasonable basis which results in no imposition of backup withholding, you are subject to a penalty of $500.

(3)           Criminal Penalty for Falsifying Information. If you willfully falsify certifications or affirmations, you are subject to criminal penalties including fines and/or imprisonment.

(4)           Misuse of TIN. If the payer discloses or uses TINs in violation of federal law, it may be subject to civil and criminal penalties.

FOR ADDITIONAL INFORMATION CONTACT YOUR TAX CONSULTANT OR THE IRS.

________________

* Unless otherwise noted herein, all references below to section numbers or to regulations are references to the Internal Revenue Code of 1986, as amended, and the regulations promulgated thereunder.