OMAHA, Neb. -- Warren Buffett's has company trimmed its stake in Chinese electric car and battery maker BYD for the first time since it bought the shares in 2008, an investment that has soared in value.Berkshire Hathaway said in a regulatory filing Tuesday with the Hong Kong stock exchange that it had sold 1.33 million of its BYD shares for roughly $47 million ($368.8 million Hong Kong dollars).Berkshire paid $232 million for the 225 million BYD shares it bought in 2008. By the end of last year, the value of those shares had ballooned to nearly $7.7 billion. The success...