Shares in Dixons Carphone (LON:DC) sunk over 20 percent at market open on Tuesday, after reporting a weak performance in the UK for both the electrical and mobile division.

The company warned that full-year profit would fall by 21 percent, expecting pre-tax profits of £382 million for 2017-18, down from £501 million last year.

The company’s UK & Ireland business saw revenue fall 1 percent, despite rising 2 percent on a like-for-like for basis. The group warned that the weakness in the UK was due to a “challenging UK mobile market and current contractual constraints”.

Looking at the company as a whole, revenues rose by 3 percent for the full year, while like-for-like revenues rose 4 percent supported by strong international performance. The UK’s weak performance was offset by a strong performance in the Nordics and Greece, which reported revenues of 10 percent and 18 percent respectively.

“With a softer computing market, our category mix during the year shifted towards consumer electronics and white goods, and online sales saw another year of double digit growth, ahead of the market,” Alex Baldock, Group Chief Executive, said.

“Right now, with our international business in good shape, we’re focusing early action on the UK. In electricals, we’re focused on gross margin recovery. In mobile, we’re stabilising our performance through improvements to our proposition and network agreements”.

For the 2018-2019 financial year, the group expects headline profit before tax to come in at around £300 million.

Shares in Dixons Carphone (LON:DC) are currently trading down 23.74 percent at 178.00 (0810GMT).