Berkshire Hathaway Vice Chairman Charlie Munger on Friday stuck by Chinese auto maker BYD <1211.HK>, which has become one of Berkshire's most controversial investments amid poor performance and revelations about its business practices.

At a meeting with investors, Munger acknowledged BYD had challenges but said he intended to keep supporting the company. BYD has bet its future on electric cars that run on advanced battery technology.

The stuff they're doing is difficult. They have 20,000 engineers working on it, the 87-year-old Munger told a few hundred investors gathered at the convention center here. I think I will hold my BYD stocks while it works out. All the way till the end.

In addition to Berkshire's stake of nearly 10 percent, Munger also holds a personal position in the company. He brought BYD to the attention of Berkshire CEO Warren Buffett, whose conglomerate owns businesses from insurance to ice cream.

Earlier this week, BYD reported an 84 percent drop in quarterly earnings, as its first-quarter domestic auto sales fell nearly 28 percent from a year earlier.

As BYD's performance has waned, so has its share price. While the company is still worth well more than it was when Berkshire bought in during the financial crisis, it has also lost much of the gains it made after the investment.

Given that performance, BYD has come up frequently whenever Munger or Buffett meet with shareholders.

BYD has also attracted controversy because of allegations it copies the industrial designs of other major automakers. Earlier this year, U.S. diplomatic cables released by WikiLeaks showed American diplomats in China had raised concerns about BYD's behavior.

Munger also told the investors and admirers who flocked to Pasadena that this would be the last gathering he would hold. Munger appears with Buffett every year at Berkshire's annual meeting in Omaha, but he has also done his own yearly meeting for his Wesco Financial business.

Now that Berkshire has acquired Wesco, he indicated the meetings would end.

(Reporting by Mary Slosson, Writing by Ben Berkowitz in New York, Editing by Gary Hill)

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