AMAGASAKI, Japan (Reuters) - Panasonic maker Matsushita said it planned to start selling plasma TVs next year that consume half as much power as its current models. Matsushita Electric Industrial Co Ltd also said it had developed a plasma TV just 24.7 mm (1 inch) thick -- quarter the thickness of its standard model, and it will start using this technology in products in the business year from April 2009.