Washington, D.C. 20549


FORM 12b-25




(Check one):

o Form 10-K

o Form 20-F Form

x 11-K Form

o 10-Q Form

o 10-D Form



o Form N-CSR











For Period Ended:

December 31, 2005


Transition Report on Form 10-K



Transition Report on Form 20-F



Transition Report on Form 11-K



Transition Report on Form 10-Q



Transition Report on Form N-SAR



For the Transition Period Ended:




Commission File Number


Read Instruction (on back page) Before Preparing Form. Please Print or Type.

Nothing in this form shall be construed to imply that the Commission has verified any information contained herein.


If the notification relates to a portion of the filing checked above, identify the Item(s) to which the notification relates:





SEI Employee Savings Investment Plan ____________________________________________________________________________________________________

Full Name of Registrant



Former Name if Applicable


201 Evans Lane


Address of Principal Executive Office (Street and Number)


St. Louis, Missouri, 63121


City, State and Zip Code


PART II — RULES 12b-25(b) AND (c)


If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to

Rule 12b-25(b), the following should be completed. (Check box if appropriate)




The reason described in reasonable detail in Part III of this form could not be eliminated without unreasonable effort or expense;



The subject annual report, semi-annual report, transition report on Form 10-K, Form 20-F, Form 11-K, Form N-SAR or Form N-CSR, or portion thereof, will be filed on or before the fifteenth calendar day following the prescribed due date; or the subject quarterly report or transition report on Form 10-Q or subject distribution report on Form 10-D, or portion thereof, will be filed on or before the fifth calendar day following the prescribed due date; and



The accountant’s statement or other exhibit required by Rule 12b-25 has been attached if applicable







State below in reasonable detail why Forms 10-K, 20-F, 11-K, 10-Q, 10-D, N-SAR, N-CSR, or the transition report or portion thereof, could not be filed within the prescribed time period.


Due to SEI Employee Savings Investment Plan’s (the Plan) change in certifying accountants, the Plan’s December 31, 2005 financial statements and corresponding audit will not be completed in time to file the Plan’s Annual Report on Form 11-K (the “2005 11-K”) within the prescribed period without unreasonable effort or expense. The registrant represents that the 2005 11-K will be filed no later than the fifteenth calendar day following the date on which it was due.


SEC 1344 (05-06) Persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.


(Attach extra Sheets if Needed)





Name and telephone number of person to contact in regard to this notification



Richard A. Schneider







(Area Code)


(Telephone Number)




Have all other periodic reports required under Section 13 or 15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months (or for

such shorter) period that the registrant was required to file such report(s) been filed ? If answer is no, identify report(s).

x Yes o No






Is it anticipated that any significant change in results of operations from the corresponding period

for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof

oYes x No





If so, attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made.


SEI Employee Savings Investment Plan

(Name of Registrant as Specified in Charter)


has caused this notification to be signed on its behalf by the undersigned hereunto duly authorized.




June 28, 2006


/s/ Richard A. Schneider




Executive Vice President and Chief Financial Officer of DRS Technologies, Inc., Plan Administrator



INSTRUCTION: The form may be signed by an executive officer of the registrant or by any other duly authorized representative. The name and title of the person signing the form shall be typed or printed beneath the signature. If the statement is signed on behalf of the registrant by an authorized representative (other than an executive officer), evidence of the representative’s authority to sign on behalf of the registrant shall be filed with the form.



Intentional misstatements or omissions of fact constitute Federal Criminal Violations (See 18 U.S.C. 1001).