Leam Transport, Ltd., a subsidiary of Leam Transportation, 1806 Big Horn, Houston, Texas 77090, has applied to the Maritime Administration for a Title XI guarantee to aid in financing the construction of six 180-foot, oceangoing tug/supply vessels.

The diesel-powered 1,250-horsepower vessels are to operate in the Gulf of Mexico. Halter Marine, Inc., New Orleans, is the proposed builder. Deliveries are scheduled between January and June 1982.

If approved, the Title XI guarantee would cover $21,400,000, or 87 1/2 percent of the estimated cost of $24,457,132.