Not really in the modern folding-bike sense. Marin is best known for mountain bikes (e.g., Bear Valley, Palisades, Team Marin) and hybrids. In 1998, they did not produce a dedicated folding “portable” bike like Brompton or Dahon.
This was the "halo bike" of the year. Marin had been experimenting with titanium (Ti) for a few years, but the 1998 catalogue solidified their commitment to the metal. marin catalogue 1998 portable