Report of Independent Registered Public Accounting Firm

To the Members of Growth Capital Master Portfolio LLC:

In planning and performing our audit of the financial
 statements of Growth Capital Master Portfolio LLC
(the Fund) as of and for the period ended March 31
2011 in accordance with the standards of the Public
Company Accounting Oversight Board (United States)
we considered the Funds internal control over financial
reporting including controls over safeguarding
securities as a basis for designing our auditing
procedures for the purpose of expressing our opinion on
the financial statements and to comply with the
requirements of Form N-SAR but not for the purpose of
expressing an opinion on the effectiveness of the Funds
internal control over financial reporting. Accordingly
we express no such opinion.

The management of the Fund is responsible for
establishing and maintaining effective internal control
over financial reporting. In fulfilling this
responsibility estimates and judgments by management
are required to assess the expected benefits and related
costs of controls. A funds internal control over
financial reporting is a process designed to provide
reasonable assurance regarding the reliability of
financial reporting and the preparation of financial
statements for external purposes in accordance with
generally accepted accounting principles. A funds
internal control over financial reporting includes those
policies and procedures that (1) pertain to the
maintenance of records that in reasonable detail
accurately and fairly reflect the transactions and
dispositions of the assets of the fund; (2) provide
reasonable assurance that transactions are recorded as
necessary to permit preparation of financial statements
in accordance with generally accepted accounting
principles and that receipts and expenditures of the
fund are being made only in accordance with authorizations
 of management and directors of the fund; and (3) provide
reasonable assurance regarding prevention or timely
detection of unauthorized acquisition use or disposition
of a funds assets that could have a material effect on
the financial statements.

Because of its inherent limitations internal control
over financial reporting may not prevent or detect
misstatements. Also projections of any evaluation of
effectiveness to future periods are subject to the risk
that controls may become inadequate because of changes
in conditions or that the degree of compliance with the
policies or procedures may deteriorate.

A deficiency in internal control over financial reporting
exists when the design or operation of a control does not
allow management or employees in the normal course of
performing their assigned functions to prevent or detect
misstatements on a timely basis. A material weakness is a
deficiency or a combination of deficiencies in internal
control over financial reporting such that there is a
reasonable possibility that a material misstatement of
the funds annual or interim financial statements will
not be prevented or detected on a timely basis.

Our consideration of the Funds internal control over
financial reporting was for the limited purpose described
in the first paragraph and would not necessarily disclose
all deficiencies in internal control that might be material
weaknesses under standards established by the Public Company
Accounting Oversight Board (United States). However we
noted no deficiencies in the Funds internal control over
financial reporting and its operation including controls
over safeguarding securities that we consider to be a
material weakness as defined above as of March 31 2011.

This report is intended solely for the information and use
of management and the Members of the Growth Capital Master
Portfolio LLC and the Securities and Exchange Commission
and is not intended to be and should not be used by anyone
other than these specified parties.

         /s/ Ernst & Young LLP


Columbus Ohio
May 26 2011