As of August 30, 2015, no live official trademarks were found on USPTO.gov for the exact terms
The singular NY Literary Agent could be developed into a New York literary agent's professional website. As literary agents move into the 21st century, having their own websites with a great and apt URL may be the difference between being a successful agent with multi-million dollar clients or a lone agent just scrabbling for a living.
The plural NY Literary Agents could be developed into an online directory of New York literary agents who have an online presence. An online directory, as opposed to a print version, could be updated regularly.
Domains Sold Separately.