Shares of 99 Cents Only Stores gained more than 10 percent Monday following reports that private equity firm Apollo Management might buy the chain.

The New York Post reported that Apollo is preparing a bid for the discount retailer, which is based in Commerce. The Post, citing an anonymous source, also reported others might enter bids.

The Schiffer-Gold family, which controls about a third of 99 Cents’ stock, approached the company’s board in March with a deal to take the company private. Its offer, which included private equity firm Leonard Green & Partners of Santa Monica, valued the company at $1.3 billion.

Analysts called the offer low-ball and predicted shareholders wouldn’t approve it, prompting the company to look for better offers.

Shares closed up $1.42, or 8.6 percent, to $18 on the New York Stock Exchange.