The FTSE 100 group, which sells software to banks and retailers that use legacy IT systems, said it would start buying shares today (Wednesday 17 July) and continue to do so until 23 October.
Bosses described the US$200mln buyback as “an initial tranche”, and said they could look at extending the programme.
The share price has taken a battering so far this month, down by almost a quarter after its half-year results were met with a few groans in the City.
Shortly after, it came out that executive chairman Kevin Loosemore had sold a chunk of shares worth almost £12mln.
Shares were down 1.3% to 1,662p in early deals on Wednesday.