Cable company Ziggo on Thursday issued a profit warning after admitting it is taking more effort than expected to keep existing clients.

The company had forecast a rise in full year operating profit of between 2.5% and 3.5% but now says it will be around 1%.

The downward revision is due to the high investments the company is having to make to keep clients on board. The company’s turnover forecast has also been revised down.

Second quarter sales rose 1.4% to €393m while net profit rose from €64m to €89m.

The company is to boost spending on winning new clients for Ziggo’s new mobile services which will be launched from August, chief executive Bernard Dijkhuizen said in a statement.

Ziggo was founded five years ago following the merger of three separate cable operators and has 55% of the Dutch market. It was floated on the Amsterdam stock exchange in 2012.