MESA INC., Dallas, offered to convert 100,000 public and private fleet vehicles in Louisiana to run on compressed natural gas. The offer includes installation of fueling equipment. In exchange, fleet operators would agree to purchase CNG from MESA at the equivalent price they pay for gasoline. Fleets account for about 300,000 of Louisiana's 3 million registered vehicles, MESA said. The company made a similar conversion offer to fleets in Phoenix (OGJ, June 1 5, p. 31 ).