When an offer has been made to purchase the shares or assets of a corporation, the purchaser may require a lock up to prevent the corporation from seeking out any other competitive offers, or from transferring its assets or shares to a third party during the lock up period. The offeror can use the lock up period to conduct due diligence, to arrange financing and to prepare the legal documentation for the deal. The clause will also prohibit various other activities in an effort to prevent the corporation from circumventing the lock up. The clause usually requires the corporation to notify the offeror if it receives another offer during the lock up period, and may require the corporation to provide the offeror with a copy of the other offer. The lock up period is often tied to any exclusivity period.