Online food delivery firm Just Eat has hailed an "excellent" start to the year, with surging profits and sales leading the company to raise its full-year revenue guidance.

Pre-tax profits rose 46% to £49.5 million in the six months to June 30, while revenues shot up 44% to £247 million.

Order numbers increased 24% to 80.4 million in the period, with solid improvement in the UK as well as its international business, which accounts for over 40% of total revenue.

In a statement, Just Eat said its first half sales were ahead of management expectations, leading it to raise its revenue guidance for 2017 to between £500 million to £515 million, up from £480 million to £495 million.

Interim chairman Andrew Griffiths said it had been "another excellent period of progress" and praised the team for "their hard work and focus at a time of significant change in senior leadership".

It comes as Just Eat is experiencing management upheaval with its new chief executive Peter Plumb due to join in September, after David Buttress was forced to step down in February due to "urgent family matters". Chairman John Hughes died in June, leaving Mr Griffiths to step in as interim chairman.

The firm is also facing a full-blown investigation into its takeover of rival Hungryhouse amid concerns the deal could curb competition.

Nevertheless, Mr Griffiths sounded a positive note on the outlook, saying: "Today's results, recent appointment of Peter Plumb as chief executive officer and the very substantial headroom for further growth in all of our territories mean that we are exceptionally well-placed as we enter the second half of the year."

The group said it was investing the extra revenue into "profitable growth opportunities", including "increased collaboration with branded UK restaurants".

Guidance for full year underlying earnings is unchanged at between £157 million and £163 million.