Is the money the husband will get in exchange for convincing the company owner to vacate the property halal?

If it is in the company owner's interest to vacate the property, then there is no objection for the husband to persuade the property owner to terminate the contract, because by doing so, he brings benefit to both parties. There is also no objection for him to take the agreed-upon money from the property owner, as it is considered a brokerage fee.