Weschler, 50, will start at the company early next year and work with Todd Combs, who joined Berkshire last year, to manage its equity portfolios.
Buffett, 81, has said he may also bring in a third manager, but meanwhile he continues to oversee the lion’s share of the company’s $52.36bn (£33bn) in US equities.
Weschler, like Combs before him, has succeeded while keeping a low profile far from the canyons of Wall Street.
The Virginia-based money manager delivered total gains of 1,236 per cent over the last 11 years, according to investors. Over the same period, Berkshire’s own Class B shares have risen 84 per cent and the S&P 500 index has fallen nearly 23 per cent.
As of 30 June, Weschler’s Peninsula Capital Advisors had long positions in about $2bn worth of stock, according to regulatory filings. Combs was managing about $400m when he was hired.