EXHIBIT 4.18

                 AMENDMENT NUMBER TEN TO AMENDED AND RESTATED
                           LOAN AND SECURITY AGREEMENT

      This  Amendment  Number  Ten to Amended  and  Restated  Loan and  Security
Agreement  ("Amendment")  is  entered  into as of March 1,  2001 by and  between
FOOTHILL CAPITAL CORPORATION,  a California corporation ("Foothill"),  and PORTA
SYSTEMS CORP., a Delaware corporation ("Borrower"), in light of the following:

      A. Borrower and Foothill have previously entered into that certain Amended
and Restated  Loan and  Security  Agreement,  dated as of November 28, 1994,  as
amended as of February 13,  1995,  March 30,  1995,  March 12, 1996,  August 26,
1997,  November 30, 1997,  August 1, 1998,  December 1, 1998, March 24, 2000 and
June 9, 2000 (collectively, the "Agreement").

      B. Borrower and Foothill desire to further amend the Agreement as provided
for and on the conditions herein.

      NOW,  THEREFORE,  Borrower  and  Foothill  hereby  amend the  Agreement as
follows:

      1.  DEFINITIONS.  All initially  capitalized  terms used in this Amendment
shall  have the  meanings  given to them in the  Agreement  unless  specifically
defined herein.

      2.  AMENDMENTS.  The  following  amendments  to  the  Agreement  shall  be
effective from the date hereof through and including July 2, 2001.

      A. Section 2.5 of the Agreement is amended to provide that interest at the
rate of 12% per annum shall be paid monthly  with  one-half of such payment made
on the first of each month and the remaining one-half being paid on the 15th day
of each month.

      B. The  facility  fee in Section  2.8 of the  Agreement  shall be deferred
until the earlier of the  termination  of the  Agreement  or until  Borrower has
consummated  a sale of stock or some or all of its assets  other  than  ordinary
course of sales of  Inventory,  at which time the net proceeds  shall be used to
pay the deferred facility fee.

      C. The $400,000 principal payment on the Indebtedness that is due on April
1, 2001 pursuant to Section 2.9 of the  Agreement,  shall be deferred  until the
earlier of the  termination of the Agreement or until Borrower has consummated a
sale of stock or some or all of its assets other than  ordinary  course of sales
of Inventory,  at which time the net proceeds  shall be used to pay the April 1,
2001 principal payment.

      D. During the period from the date of this Amendment through July 2, 2001,
Borrower shall not make any payments on Indebtedness to any subordinated


                                       1


creditors,  but Borrower shall not be prohibited from paying accounts payable in
the ordinary course of business.

      E.  Upon  the  consummation  of any  sale of  assets  or sale of  stock by
Borrower or any of its  subsidiaries,  100% of the net  proceeds  from such sale
shall be  delivered  to  Foothill  to be  applied  first to  accrued  and unpaid
interest,  second to the deferred  facility fee, third to the principal  payment
due April 1, 2001, and fourth to the Obligations.

      3.  REPRESENTATIONS  AND  WARRANTIES.  Borrower hereby affirms to Foothill
that all of Borrower's representations and warranties set forth in the Agreement
are true, complete and accurate in all respects as of the date hereof

      4. NO  DEFAULTS.  Borrower  hereby  affirms to  Foothill  that no Event of
Default  has  occurred  and is  continuing  as of the date  hereof,  except  for
defaults related Section 6.13(a)  (interest  coverage  covenant) and section 2.4
(borrowings in excess of borrowing  base  formula),  both of which are expressly
waived through the term of this Amendment. (July 2, 2001)

      5. CONDITION  PRECEDENT.  The effectiveness of this Amendment is expressly
conditioned upon receipt by Foothill of an executed copy of this Amendment

      6. COSTS AND  EXPENSES.  Borrower  shall pay to Foothill all of Foothill's
out-of-pocket costs and expenses  (including,  without limitation,  the fees and
expenses of its  counsel,  which  counsel may include any local  counsel  deemed
necessary, search fees, filing and recording fees, documentation fees, appraisal
fees,  travel  expenses,   and  other  fees)  arising  in  connection  with  the
preparation,   execution,  and  delivery  of  this  Amendment  and  all  related
documents.

      7.  LIMITED  EFFECT.  In the  event of a  conflict  between  the terms and
provisions of this Amendment and the terms and provisions of the Agreement,  the
terms and provisions of this Amendment shall govern. In all other respects,  the
Agreement,  as amended and supplemented  hereby,  shall remain in full force and
effect.

      8.  COUNTERPARTS:  EFFECTIVENESS.  This  Amendment  may be executed in any
number of counterparts and by different parties on separate  counterparts,  each
of which when so executed and delivered  shall be deemed to be an original.  All
such counterparts,  taken together, shall constitute one and the same Amendment.
This  Amendment  shall become  effective  upon the execution of a counterpart of
this Amendment by each of the parties hereto.


                                       2

      IN WITNESS WHEREOF,  the parties hereto have executed this Amendment as of
the date first set forth above.

                                             FOOTHILL CAPITAL CORPORATION,
                                             a California corporation


                                              By ______________________________
                                              Title: __________________________


                                              PORTA SYSTEMS CORP.,
                                              a Delaware corporation


                                              By ______________________________
                                              Title: __________________________