NEW YORK ( TheStreet) -- BJ's Wholesale ( BJ)is surging following a recommendation from a private-equity firm that the retailer be taken private. Green Equity Investors purchased about 5.1 million shares of BJ's stock, according to a Securities and Exchange Commission filing. In the filing, the firm said BJ's shares are undervalued and wishes to discuss with management ways to enhance shareholder value. "These discussions may include a 'going-private' transaction, new financings (potentially through mortgage financings or sale leaseback transactions) or other similar transactions," Green Equity said. Shares of BJ's are spiking 12.4% to $41.56 in midday trading, Thursday. -- Reported by Jeanine Poggi in New York. Follow TheStreet.com on Twitter and become a fan on Facebook.