Exhibit 10.46**THIRD AMENDMENT TO THE****BIOMED REALTY, L.P. 401(K) RETIREMENT SAVINGS PLAN**     THIS AMENDMENT is executed by BIOMED REALTY, L.P. (the “Employer”) and GARY KREITZER andJOHN WILSON (individually or collectively the “Trustee”).     WHEREAS, the Employer previously adopted the BIOMED REALTY, L.P. 401(K) RETIREMENT SAVINGSPLAN (the “Plan”);     WHEREAS, the Plan provides the Employer may amend the Plan; and     WHEREAS, the Employer desires to amend the Plan.     NOW, THEREFORE, the Plan is hereby amended in the following particulars only;     Paragraph P of Article I is deleted and replaced with the following:1. Last Day Employment and Hours of Service Required. Allocations of Nonelective EmployerContributions and unallocated forfeitures, if applicable, shall be made only to the appropriateAccounts of those persons who are Participants, who have completed 1000 Hours of Service during thePlan Year, and who are in the employ of the Employer on the last day of the Plan Year.          If a Plan Year is less than 12 months, the required number of hours shall be redetermined bymultiplying 1000 Hours of Service by the product of one-twelfth (1/12) and the number of months insuch Short Plan Year.          If the allocation requirements of this paragraph result in an allocation that does not satisfythe coverage requirements of Section 410(b)(1)(B) of the Code in any Plan Year then additionalNonelective Employer Contributions shall be made no later than the due date of the Employer’s taxreturn and shall be allocated retroactive to the last day of that Plan Year to otherwise eligibleParticipants to the extent necessary to satisfy coverage requirements of Section 410(b)(1)(B) ofthe Code. In determining the extent to which such allocations to such Participants are necessary,allocations shall first be made to the Participants who have less than 1,000 Hours of Servicebeginning with the Participant with the smallest Compensation and allocations shall continue to bemade to such Participants with increasing Compensation until the coverage requirements of the ratiopercentage test of Section 410(b)(1)(B) of the Code are satisfied. If, after such allocation, thecoverage requirements of the Code are still not satisfied, then Participants who have terminatedservice with more than 500 Hours of
 

 
Service during the Plan Year shall also be included in the allocation pursuant to this provision tothe extent necessary to satisfy the coverage requirements of the Code. In determining the extentto which such allocations to terminated Participants are necessary, allocations shall first be madeto the terminated Participant with the smallest Compensation and allocations shall continue to bemade to terminated Participants with increasing Compensation until the coverage requirements of theCode are satisfied. Terminated Participants must have been credited with more than 500 Hours ofService prior to termination to be eligible for an allocation pursuant to this provision.          2. Retirement, Death, and Disability. The last day of employment and minimum Hours ofService requirements of this Paragraph P shall not apply to a Participant who terminates employmentduring the Plan Year by reason of retirement at or after Normal Retirement Age or death or TotalDisability.          3.Last Day Employment and Service — Not Required. Allocations of ElectiveContributions, Matching Contributions, Qualified Matching Contributions and Qualified NonelectiveEmployer Contributions shall be made to the appropriate Accounts of Eligible Participants duringthe Plan Year.     This Amendment shall not reduce the Account Balance of any Participant determined as ofthe later of December 31, 2005 or the date this Amendment is adopted.     This Amendment shall be effective as of January 1, 2006.     IN WITNESS WHEREOF, the Employer and the Trustee executes this Amendment on this 27th day ofFebruary, 2006.     EMPLOYER: TRUSTEE:  BIOMED REALTY, L.P.         /s/ GARY A. KREITZER /s/ GARY A. KREITZER         Gary Kreitzer         /s/ JOHN F. WILSON         John Wilson