Exhibit 4.3.o.




                                INSIDER LETTER


                                 July 12, 2006
                                      --


Viceroy Acquisition Corporation
8235 Forsyth Boulevard
Suite 400
St. Louis, Missouri 63105


CRT Capital Group LLC
262 Harbor Drive
Stamford
Connecticut 06902


KBC Peel Hunt Ltd
111 Old Broad Street
London
EC2N 1PH


         Re: Offering of Units
         ---------------------

Gentlemen:

         The undersigned shareholder of Viceroy Acquisition Corporation (the
"COMPANY"), in consideration of CRT Capital Group LLC ("CRT") and KBC Peel
Hunt Ltd ("KBC") agreeing to act as placement agents in the offering
("OFFERING") of 22,500,000 units (the "UNITS"), each Unit consisting of one
share of common stock in the capital of the Company, par value $0.0001 per
share (the "SHARES"), and one warrant (the "WARRANTS"), each Warrant
entitling the holder to purchase one Share, as more particularly explained
in the offering circular of the Company in connection with such Offering
(the "OFFERING CIRCULAR") and embarking on the placement process, hereby
agrees as follows:

         1.       Until the earlier of (a) the completion by the Company of a
Qualified Business Combination and (b) the distribution of all amounts held in
the Trust Fund following the failure by the Company to complete a Qualified
Business Combination by the Qualified Business Combination Deadline, to the
extent the Company solicits the approval of his shareholders for a Business
Combination, the undersigned irrevocably agrees to vote all Founding Shares
owned by him and the Shares included in Units purchased by the undersigned in
the Offering in accordance with the majority of the votes cast by the New
Shareholders.

         2.       In the event that the Company fails to complete a Business
Combination by the Qualified Business Combination Deadline, the undersigned
will take all reasonable actions

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within his power to cause the Company to liquidate as soon as reasonably
practicable. On such a liquidation, the undersigned hereby waives any and all
right, title, interest or claim of any kind in or to any distribution of the
funds held in the Trust Fund as a result of such liquidation with respect to
his Founding Shares (any such right, title, interest or claim, a "CLAIM") and
hereby waives any Claim he may have in the future as a result of, or arising
out of, any contracts or agreements with the Company in respect of his
Founding Shares and will not seek recourse against the Trust Fund for any
reason whatsoever in respect of his Founding Shares.

         3.       In order to minimize potential conflicts of interest which
may arise from multiple corporate affiliations, the undersigned agrees to
present to the Company for his consideration, prior to presentation to any
other person or entity, any suitable opportunity to acquire a Target Business,
until the earlier of (a) the completion by the Company of a Qualified Business
Combination and (b) the distribution of all amounts held in the Trust Fund
following the failure by the Company to complete a Qualified Business
Combination by the Qualified Business Combination Deadline.

         4.       The undersigned acknowledges and agrees that until the
earlier of (a) the completion by the Company of a Qualified Business
Combination and (b) the distribution of all amounts held in the Trust Fund
following the failure by the Company to complete a Qualified Business
Combination by the Qualified Business Combination Deadline, the Company will
not complete any Business Combination which involves an entity which is
affiliated with the undersigned unless the Company obtains an opinion from an
independent investment banking firm which is a member of the National
Association of Securities Dealers, Inc. (such firm being reasonably acceptable
to each of CRT and KBC) that the Business Combination is fair to the Company's
shareholders from a financial perspective.

         5.       Until the completion by the Company of a Business Combination
neither the undersigned, nor any affiliate of the undersigned will be
entitled to receive, and will not accept, any compensation for services
rendered to the Company prior to such Business Combination; provided that
the undersigned shall be entitled to reimbursement from the Company (out of
the funds not held in the Trust Fund) for his reasonable out-of-pocket
expenses incurred in connection with seeking and completing any Business
Combination.

         6.       Until the earlier of (a) the completion by the Company of a
Qualified Business Combination and (b) the distribution of all amounts held in
the Trust Fund following the failure by the Company to complete a Qualified
Business Combination by the Qualified Business Combination Deadline, neither
the undersigned, nor any affiliate of the undersigned will be entitled to
receive or accept a finder's fee or any other compensation in the event the
undersigned, or any affiliate of the undersigned originates a Business
Combination.

         7.       The undersigned agrees to enter into an escrow agreement
with the Company and an escrow agent (such escrow agent being reasonably
acceptable to each of CRT and KBC) with respect to his Founding Shares whereby
his Founding Shares will be held in escrow for a three-year period commencing
on the Admission Date. The undersigned agrees not to amend the terms of any
escrow agreement entered into without the prior written consent of each of CRT
and KBC.

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         8.       (a) The undersigned agrees, for the purposes of, and subject
to the provisions of, Rule 7 of the AIM Rules (as further described in the
Offering Circular) and the Rule 7 Lock-in Deed, dated as of the date hereof
and executed by the undersigned, not to dispose of any interest in the Shares
or Warrants held by the undersigned, whensoever such Shares or Warrants were
purchased, for the period of one year from the Admission Date.

                  (b) The undersigned further agrees that he will not sell
or otherwise dispose of any securities of the Company owned by him including
the Shares and Warrants, except pursuant to a registration statement under
the U.S. Securities Act of 1933, as amended (the "SECURITIES ACT") or
pursuant to an exemption from such registration; provided, however, that in
the case of any sale or disposition otherwise than pursuant to a
registration statement, the undersigned shall take such steps, including
without limitation legending the certificates representing the securities,
to make sure that the securities may be segregated from the pool of
securities that are or may become tradeable in the U.S free of any
restrictions. Additionally, the undersigned will not engage in any hedging
transactions involving the securities of the Company owned by him (including
the Shares and Warrants) other than in compliance with the Securities Act.

         9.       The undersigned authorizes any employer, financial
institution, or consumer credit reporting agency to release to CRT and KBC and
their legal representatives or agents (including any investigative search firm
retained by CRT or KBC) any information they may have about the undersigned's
background and finances ("INFORMATION"). Neither CRT, KBC nor their agents
shall be violating the undersigned's right of privacy in any matter in
requesting and obtaining the Information and the undersigned hereby releases
them from liability for any damage whatsoever in that connection. The
Information obtained shall be kept confidential in perpetuity by CRT, KBC and
their legal representatives and agents except as required by law or by
judicial order.

         10.      Capitalized terms used but not defined in this letter have
the meanings given to them in the Offering Circular.

         11.      This letter shall be governed in all respects by the laws of
the State of New York.


                                     JEFFERY H. CALL



                                     /s/ Jeffery H. Call
                                     -----------------------------------------
                                                     Signature

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