definiens: ) of the Prime Lease ( as defined in the Sublease ) by SELLER to SUB or PARENT . SELLER hereby agrees that it will in good faith use commercially reasonable efforts to negotiate an assignment with BUYER and assist BUYER to effect such an assignment on terms that are reasonably acceptable to BUYER for sixty ( 60 ) days after the date of the Assignment Notice . If the Assignment is not complete within said sixty ( 60 ) day period, SELLER shall not be obligated to make further efforts with respect to the Assignment ; provided, however, that so long as BUYER, SELLER and Prime Lessor have made and continue to make significant progress in the negotiation of the Assignment, SELLER shall continue in good faith to make commercially reasonable efforts to complete the Assignment for a reasonable period of time after said sixty ( 60 ) day period . BUYER agrees that it will reimburse SELLER and Prime Lessor for all costs and expenses incurred by SELLER or Prime Lesser, as the case may be, in connection with the Assignment regardless of whether the Assignment is executed, including attorney 's fees ; provided that, BUYER shall not reimburse or pay to SELLER and/or Prime Landlord, any consideration for the Assignment unless BUYER has provided its prior consent to such consideration . However, SELLER shall not be required to pay Prime Landlord any consideration for the Assignment . BUYER acknowledges and agrees that in accepting any such assignment of the Prime Lease it shall also assume all of SELLER 's obligations under any subleases of the Premises ( as defined in the Sublease ) . BUYER further agrees that it shall provide Prime Landlord and SELLER with reasonable and customary guarantees and indemnities in the documentation related to the assignment of the Prime Lease, including without limitation an indemnity by the assignee in favor of the SELLER for any loss, cost or damage that SELLER may incur under the Prime Lease from and after the date of the Assignment and a guaranty of such indemnity by PARENT if SUB is the assignee . In addition, BUYER understands and agrees that in the event that the Assignment is effected, upon the effective date of the Assignment, all of SELLER 's obligations and agreements related to and contained in the third full paragraph of Section 6 of the Sublease ( i.e., the obligations and agreements related to as such term is defined in the Sublease ) shall be extinguished and void and shall no longer be enforceable against BUYER or SELLER