Supermarket chain Albertsons is exploring a bid for upscale grocer Whole Foods, according to people familiar with the matter.

Sources said Albertsons, owned by New York private equity firm Cerberus Capital Management, had a preliminary chat with bankers about a potential takeover of the high-end food chain, though no formal action has taken place, Financial Times reports. Talks of a bid surfaced after activist investor Jana Partners pressured Whole Foods to speed up its turnaround plans and explore a sale to combat stagnant growth. Jana Partners holds an 8.8% stake in the upscale organic food grocer.

In response to the investment firm's demands, Whole Foods is seeking counsel from investment banker Evercore Partners to review its business operations and the possibility of a sale.

This would not be Albertsons first takeover of a major brand. In 2015 the chain, which operates 2,200 stores, acquired Safeway for $9B, making it the largest supermarket chain in terms of revenue, trailing behind Walmart and Kroger.