How much can a landlord raise the rent in a union city, nj condo?

Whatever the market will bear.

Scott,

I am still at square one with your response... thanks for your help anyway.

Unless you are in a rent controlled unit a landlord can increase rental at the beginning of a new lease term. There are no specific laws limiting the amount of the increase. However, an increase has to be considered fair and reasonable. A court can take into account several factors in determining this.

This site has more details. http://www.nj.gov/dca/divisions/codes/publications/pdf_lti/rnt_incrse_bultin.pdf

If you are in a rent control unit , it has to be approved.

But assuming it is not, they are free to set their rent at current market value.