Is it copyright infringement to reference a trade name within an article?

Mere reference is likely to be protected under "Fair Use". You seem to be confusing trademark and copyright protection, they are different things. A trademark protects an identifying mark/phrase/logo used in commerce- in a word, the owner is entitled to prevent a likelihood of confusion with another thing. A copyright protects a creative work fixed in a tangible medium.

The bank can't force you to remove the reference on the grounds that it infringes their copyright because the bank has no copyright ownership in another's work (the articles on your web site). It also can't object to your using its trade name because there's very little protection for trade names. And how else are you going to refer to the business except by using its name. It may have a valid object to the use of its trademark on a couple of grounds: 1) if you're using the mark without acknowledging that it is a trademark that belongs to this particular company, 2) if the information contained in the article is defamatory or derogatory, or 3) if the articles on the site are somehow misleading or the bank does not want the author's name associated with its services. Ask the bank to clarify its reason for objecting, what specifically it objects to, and why the only solution is to pull all of the web pages.