China-based electric-vehicle maker BYD wants to get an extra charge out of the public investment market. The company said last week that it will sell about $550 million worth of stock on the Hong Kong stock exchange. That'd be the largest single offering since the company went public in 2002.

BYD is looking to raise cash in order to boost its investment in electric powertrain technology development while also cutting debt. The company's debt rose about 34 percent last year, while first-quarter profit fell 89 percent on lower demand for its gas-powered vehicles. Warren Buffet's Berkshire Hathaway owns about 28 percent of the company, according to Bloomberg News.

Earlier this month, BYD said it received an order for 2,000 battery-electric buses and 1,000 electric taxis from the city of Hangzhou, China. That good news came on the heels of BYD losing a 10-bus, $12.1 million contract from the city of Long Beach, CA, because of compliance issues with the federal government (the feds were funding some of that money). Earlier this year, BYD received an order for up to 1,200 electric buses from the Chinese city of Dalian. Meantime, the link to the BYD offering announcement is here (PDF).