Chinese e-commerce giant Alibaba Group Holding Ltd. is aiming to handle one trillion yuan ($157 billion) of transactions in 2012 on its Taobao consumer sales platforms, the company’s Chairman Jack Ma said Saturday. Speaking at Alibaba Group’s annual convention in Hangzhou, China, Mr. Ma said that the websites, consumer-to-consumer trade platform Taobao Marketplace, and business-to-consumer platform Taobao Mall, which were recently split into separate business units, will help spur consumer demand in the world’s most populous nation. Taobao as a whole handled nearly 400 billion yuan of online transactions last year.