<PAGE>

                              EXTENSION OF LEASE


This Indenture, made this 7th day of December, 1995 by and between Lutheran
Brotherhood, a Minnesota corporation (hereinafter called "Landlord") and ADC
Telecommunications, Inc., a Minnesota corporation, (hereinafter called
"Tenant").

                                  WITNESSETH:

WHEREAS, Landlord and Tenant entered into a certain lease agreement, dated
August 21, 1990, as amended by that certain First Amendment to Lease Agreement
dated October 26, 1990, (hereinafter called the "Lease") under which Landlord
demised to Tenant the premises commonly known as 5900 Clearwater Drive,
Minnetonka Corporate Center (hereinafter, the "Leased Premises"); and

WHEREAS, the initial term of said Lease is scheduled to expire by lapse of time
on August 31, 1996; and

WHEREAS, Landlord and Tenant hereby wish to extend the term of said Lease; and

WHEREAS, Landlord and Tenant have agreed upon the terms and conditions
governing said extension;

NOW, THEREFORE, in consideration of the premises, the payments to be made
hereunder and the covenants and agreements herein undertaken to be kept and
performed, it is agreed as follows:

1.   The term of the Lease is hereby extended for a period of five (5) years
commencing on the last day of the initial term of the Lease and expiring on the
31st day of August, 2001, (hereinafter, the "Extension Period") unless the
Lease shall sooner terminate as provided therein.

2.   For years 1 (l) through three (3) of the Extension Period, Tenant shall
pay to Landlord, as Base Rent, over and above the other and additional payments
to be made by Tenant for the Leased Premises, the annual sum of Three Hundred
Seventy Eight Thousand, Six Hundred Twelve and No/100 Dollars ($37~,612.00)
payable monthly in advance on the first day of each and every calendar month in
installments of Thirty One Thousand Five Hundred Fifty One and No/100 Dollars
($31,551.00), and for years four (4) through five (5) of the Extension Period,
the annual sum of Four Hundred Sixteen Thousand, Seven Hundred Sixty and No/100
Dollars ($416,760.00) payable monthly in advance on the first day of each and
every calendar month in installments of Thirty Four Thousand Seven Hundred
Thirty and No/l 00 Dollars ($34,730.00) all at the place and in the manner as
provided for within the Lease.

                                       1
<PAGE>
3.   It is understood and agreed that Tenant will continue to be responsible
for 100% of the Leased Premises' annual real estate tax and insurance expense
as defined in the Lease and that Tenant will have no further options to extend
the Lease. Except as herein specifically amended, all other terms, covenants
and conditions of the Lease shall remain in full force and effect, and the same
are hereby ratified and confirmed.

IN WITNESS WHEREOF, Landlord and Tenant have executed the within Agreement as
of the day and year first above written.

LANDLORD:

Lutheran Brotherhood
a Minnesota corporation


  /s/ Clifford W. Habeck
------------------------------------
By:   Clifford W. Habeck
Its:  AVP

TENANT:

ADC Telecommunications, Inc.


  /s/ Robert E. Switz
------------------------------------
By:   Robert E. Switz
Its:  VP and CFO


                                       2