Bornscheuer Bus Co. - suburban served Amityville, Copiague, Lindenhurst, West Babylon, Babylon. Affiliated company EBT formed in 1962, continues in existence under contract with Suffolk County Transit.
Louis A. Fuoco Bus Line - served Patchogue, East Patchogue, Hagerman, Bellport, South Haven, Mastic, Mastic Beach, Port Jefferson, Medford, Coram, Ridge, Calverton, Riverhead. Continued to exist during early years of Suffolk County Transit.
Huntington Coach Corp. - served Huntington, Farmingdale, Melville, Halesite.
Quinn's Bus Lines - served Suffolk County.
Suffolk Bus Corp. - served Bay Shore, Brentwood, West Brentwood, Central Islip, Islip, Babylon. Began operations in 1946, continues in existence under contract with Suffolk County Transit.
Sunrise Coach Lines - suburban served Greenport, Riverhead, Southampton, Sag Harbor, Easthampton. Began operations in 1946, continues in existence under contract with Suffolk County Transit.
Utility Lines - suburban served Freeport to Patchogue along Merrick Road and Montauk Highway.
Also reported to exist was Babylon Transit, operating from 1937 until around 1986, its final years under contract with Suffolk County Transit.