Facebook is delaying its initial public offering (IPO) on the stock markets until late next year, according to reports.

The hotly anticipated listing will not take place until September, the Financial Times reported, citing sources close to the matter. The company has not commented.

Originally, the listing was expected in April. Recent share valuations have put Facebook's market capitalisation at $66.5 billion (£42.2 billion), the paper noted.

Facebook chief executive Mark Zuckerberg is reportedly keen to delay the listing in order to keep employees focused on products.

Under US regulatory rules however, Facebook will have to report some numbers by April, the paper reported, having already passed the 500 shareholder mark. This could be a first official glimpse into revenues rumoured to have topped $1.5 billion.