Panera Bread Co, the US-based, fast-casual restaurant chain, is working with advisers to study its options after receiving takeover interest, according to a report by Bloomberg.

The report suggested that the chain, which has c2,000 sites and a market capitalisation of c$6bn, was working with advisors.

A follow-up report suggested that Starbucks could be the mystery suitor for the group, which saw its shares climbed almost 8% on the speculation.