TalkTalk boss Dido Harding has called for tough scrutiny of the multi-billion pound mergers shaking up the mobile and broadband sector as she unveiled the group's annual results.

Pre-tax profits rose 3.2 per cent to £32 million for the year to the end of March while revenues increased 4.2 per cent to £1.8 billion, accelerating in the fourth quarter and putting the business on course for five per cent growth in the current financial year.

The results come as TalkTalk faces a changing business landscape in which larger rival BT is swallowing up leading mobile operator EE for £12.5bn while Three owner Hutchison Whampoa buys O2 in a £10bn deal.

Both mergers face regulatory scrutiny though BT boss Gavin Patterson believes its move for EE should be passed by competition authorities without it having to make concessions.

Meanwhile, Ofcom is carrying out a review of the sector amid calls from the telecoms giant's rivals to split off its Openreach division which owns the UK's main broadband network.

Baroness Harding said: "We believe firmly that competition will drive the innovation and investment that Britain needs in this essential infrastructure and urge the respective regulatory bodies currently reviewing the various mergers and industry structure to put strong competition at the heart of their decisions."

TalkTalk is rolling out its own high-speed fibre broadband joint venture in York and believes it can build a UK network of around ten million households.

The firm, which positions itself as a value-for-money proposition for broadband, TV, home telephone and mobile services, said it had raised its revenue outlook for 2015/16 after year-on-year growth accelerated to six per cent in the January to March quarter.

During the period it added a net 47,000 phone and broadband deals, as well as upping numbers on fibre connections by 83,000, with 66,000 net adds for its mobile business and 82,000 in TV. Taking all four together is known as "quad play"

Harding said: "British consumers and businesses increasingly appreciate TalkTalk's value for money products, and we are focused on improving our customers' experience still further and growing our already flourishing quad play business."

During the year, Talk Talk saw thousands of broadband customers transferred from Virgin and also picked up Tesco's broadband business as well as buying the blinkbox video operation from the supermarket giant.

It said that with the integration of blinkbox now mainly complete it would "accelerate the development of our TV proposition", with its 1.4 million customers making it the third biggest pay-TV platform in the UK.

Analysts at Barclays said TalkTalk's results were broadly in line with expectations and showed "strong operational momentum and accelerating revenue growth" leaving the company "well positioned" to meet its 2016/17 targets and grow further.