Can a Landlord Just Say "No"? The meaning of "consent not to be unreasonably withheld"

Right To Assign & Sublease

A tenant is free to assign its lease of commercial premises (or sublet them) unless the lease provides otherwise. It is common for commercial leases to stipulate that the tenant will not assign the lease or sublet the premises without the landlord's prior written consent. Generally, leases also state that the landlord's consent is not to be unreasonably withheld.

When it is reasonable for a landlord to say "no"? When can a landlord be compelled to consent?

Read the full article here: Can a Landlord Just Say No - January 24- 2014