IRN-Bru manufacturer AG Barr now estimates the effective date of its planned £1.6 billion merger with larger soft-drinks company Britvic will be February 26 – nearly a month later than it had anticipated previously.

It published its revised expected timetable for the deal yesterday, following a delay in the Office of Fair Trading's decision on the deal.

Lanarkshire-based AG Barr had envisaged, before the OFT delay, that the merger would become effective on January 30.

The OFT, which has to rule on whether or not it is likely there is a serious prospect the deal might lead to a substantial lessening of competition, has put back its target decision date from January 17 to February 13.

A spokesman for the OFT told The Herald earlier this week: "You shouldn't read anything into this change of date. It is not unusual for timetables to be changed in merger assessment cases."

A prominent shareholder of AG Barr last week highlighted fears in Scotland about "significant interference" from the south following the Scottish group's merger with Hertfordshire-based Britvic.

Alan Waddell, former chairman of venerable Glasgow stockbroker Speirs & Jeffrey, raised the concern as he and other AG Barr investors approved the merger at a general meeting in Glasgow.