What is the ruling on paying a monthly sum to an official in a company in exchange for his approval of a high rental value for a building designated for rent?

That is impermissible due to the deception involved towards the company and the handling of bribery. The Prophet, peace and blessings be upon him, said: "Whoever cheats is not from me," and he also said: "The curse of Allah is upon the briber and the bribed."