PTC Therapeutics, a US-based drugs developer for muscles, plans to float on the Nasdaq stock exchange with a market capitalisation of about $322m.

PTC plans to offer 6.9 million shares at between $13 and $16 each.

PTC posted a $26m net loss on $34m in revenue for last year, compared to $30m in net income on $105m in revenue for 2011.

Investment banks JP Morgan and Credit Suisse are PTC’s lead underwriters for the initial public offering (IPO), with legal…