Shares of Penn Virginia Corp., the Radnor oil and gas exploration company, zoomed this morning after George Soros, the world's richest Democratic Party backer, his son Robert Soros, and their firms -- Soros Fund Management LLC (offices in New York), WAFO LLC (Delaware) and Quantum Partners (Cayman Islands) -- announced they've spent $29.1 million to buy a 6-million-share, 9.1% stake and want the company to consider a sale to boost their profit.

In a statement to the SEC, Soros and crew called Penn Virginia "undervalued" and said they've been pressing Penn Virginia managers about "strategic alternatives," which typically include putting a company or key assets up for sale. Penn Virginia "has been very well managed" and its bosses should be given more "incentives" -- presumably stock -- but they also need to "explore strategic alternatives as a means to enhance or maximize shareholder value." Soros also said his group may buy more Penn Virginia stock or debt and hedge its investments in the firm.