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                                                                      EX-99.CERT

                                 CERTIFICATIONS

                         Pursuant to Section 302 of the
                           Sarbanes-Oxley Act of 2002

I, Robert S. Dow, certify that:

     1.   I have reviewed this report on Form N-CSR of Lord Abbett Securities
          Trust;

     2.   Based on my knowledge, this report does not contain any untrue
          statements of material fact or omit to state a material fact necessary
          to make the statements made, in light of the circumstances under which
          such statements were made, not misleading with respect to the period
          covered by this report;

     3.   Based on my knowledge, the financial statements, and other financial
          information included in this report, fairly present in all material
          respects the financial condition, results of operations, changes in
          net assets, and cash flows (if the financial statements are required
          to include a statement of cash flows) of the Registrant as of, and
          for, the periods presented in this report;

     4.   The Registrant's other certifying officer and I are responsible for
          establishing and maintaining disclosure controls and procedures (as
          defined in Rule 30a-3(c) under the Investment Company Act of 1940) for
          the Registrant and have:

             a) designed such disclosure controls and procedures, or caused such
                disclosure controls and procedures to be designed under our
                supervision, to ensure that material information relating to the
                Registrant, including its consolidated subsidiaries, is made
                known to us by others within those entities, particularly during
                the period in which this report is being prepared; and

             b) designed such internal control over financial reporting, or
                caused such internal control over financial reporting to be
                designed under our supervision, 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; and

             c) evaluated the effectiveness of the Registrant's disclosure
                controls and procedures and presented in this report our
                conclusions about the effectiveness of the disclosure controls
                and procedures, as of a date within 90 days prior to the filing
                date of this report based on such evaluation; and

             d) disclosed in this report any change in the Registrant's internal
                control over financial reporting that occurred during the second
                fiscal quarter of the

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                period covered by this report that has materially affected, or
                is reasonably likely to materially affect, the Registrant's
                internal control over financial reporting; and

     5.   The Registrant's other certifying officer and I have disclosed to the
          Registrant's auditors and the audit committee of the Registrant's
          board of trustees (or persons performing the equivalent functions):

             a) all significant deficiencies and material weaknesses in the
                design or operation of internal control over financial reporting
                which are reasonably likely to adversely affect the Registrant's
                ability to record, process, summarize, and report financial
                information; and

             b) any fraud, whether or not material, that involves management or
                other employees who have a significant role in the Registrant's
                internal control over financial reporting.


Date: June 22, 2005


                                     /s/Robert S. Dow
                                     ----------------
                                     Robert S. Dow
                                     Chief Executive Officer,
                                     Chairman and President

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                                 CERTIFICATIONS

                         Pursuant to Section 302 of the
                           Sarbanes-Oxley Act of 2002

I, Joan A. Binstock, certify that:

     1.   I have reviewed this report on Form N-CSR of Lord Abbett Securities
          Trust;

     2.   Based on my knowledge, this report does not contain any untrue
          statements of material fact or omit to state a material fact necessary
          to make the statements made, in light of the circumstances under which
          such statements were made, not misleading with respect to the period
          covered by this report;

     3.   Based on my knowledge, the financial statements, and other financial
          information included in this report, fairly present in all material
          respects the financial condition, results of operations, changes in
          net assets, and cash flows (if the financial statements are required
          to include a statement of cash flows) of the Registrant as of, and
          for, the periods presented in this report;

     4.   The Registrant's other certifying officer and I are responsible for
          establishing and maintaining disclosure controls and procedures (as
          defined in Rule 30a-3(c) under the Investment Company Act of 1940) for
          the Registrant and have:

             a) designed such disclosure controls and procedures, or caused such
                disclosure controls and procedures to be designed under our
                supervision, to ensure that material information relating to the
                Registrant, including its consolidated subsidiaries, is made
                known to us by others within those entities, particularly during
                the period in which this report is being prepared; and

             b) designed such internal control over financial reporting, or
                caused such internal control over financial reporting to be
                designed under our supervision, 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; and

             c) evaluated the effectiveness of the Registrant's disclosure
                controls and procedures and presented in this report our
                conclusions about the effectiveness of the disclosure controls
                and procedures, as of a date within 90 days prior to the filing
                date of this report based on such evaluation;

             d) disclosed in this report any change in the Registrant's internal
                control over financial reporting that occurred during the second
                fiscal quarter of the period covered by this report that has
                materially affected, or is reasonably

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                likely to materially affect, the Registrant's internal control
                over financial reporting; and

     6.   The Registrant's other certifying officer and I have disclosed to the
          Registrant's auditors and the audit committee of the Registrant's
          board of trustees (or persons performing the equivalent functions):

             a) all significant deficiencies and material weaknesses in the
                design or operation of internal control over financial reporting
                which are reasonably likely to adversely affect the Registrant's
                ability to record, process, summarize, and report financial
                information; and

             b) any fraud, whether or not material, that involves management or
                other employees who have a significant role in the Registrant's
                internal control over financial reporting.


Date: June 22, 2005


                                     /s/ Joan A. Binstock
                                     --------------------
                                     Joan A. Binstock
                                     Chief Financial Officer and Vice President