National Australia Bank yesterday announced the sale of its Commercial Fleet business to Super Group Australia for an undisclosed price.Commercial Fleet is in the business of leasing and maintaining commercial vehicles, including buses, forklifts and trailers.The business has $342 million of assets and made $6 million of cash earnings in 2006.Last year NAB sold its car fleet leasing and maintenance business, Custom Fleet, to GE Commercial Finance. Super Group Australia, whose parent is listed on the Johannesburg Stock Exchange, is a big fleet operator and supply chain management company.The group bought Commonwealth Bank's fleet management business in 2004, its first entry into the Australian market.