Boosted by the Euro 2016 championships, TalkSport saw its weekly audience increase to 3.3 million, the station's second highest, with four of its key weekday shows breaking listener records.
The firm said pre-tax profits for the six months to June 30 came in at £4.5m, down slightly from £5m in the same period last year. Sales rose from £37m to £38.2m.
However, chairman Richard Huntingford flagged that uncertainty linked to the EU referendum was dragging on the advertising market in Ireland.
He said: "In our local stations and in Ireland, advertising trends were softer as we moved towards the referendum in Q2.
"Whilst it is still unclear what impact the uncertainty created by Brexit might have on advertising revenues in the all-important Q4, including in Ireland, the group currently anticipates a full-year outturn broadly in line with expectations."
He added that "good progress" is being made in securing regulatory clearances in connection with the News Corp offer.
The media giant behind The Sun and The Times newspapers announced in June that it was diving into the digital radio market by making a £220m swoop for Wireless.
News Corp said it had moved to snap up Wireless Group because it made an "excellent strategic fit" and would strengthen its digital business. TalkSport has the radio and digital broadcasting rights to the Premier League and the FA Cup.
The cash offer will see Wireless shareholders receive 315p per share, while named shareholders from 20 May this year will pocket a special dividend of 6.15p and a final dividend of 7.6p.
Wireless also owns Virgin Radio UK and TalkRadio. The company sold off its TV assets to ITV for £100m in February.
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