Three men convicted of belonging to a gang that plotted to bomb the London Stock Exchange and build a terrorist training camp have had their open-ended sentences changed to fixed terms.

Three London judges ruled Tuesday that the men should instead receive "determinate" fixed-length sentences.

The men were originally given indeterminate sentences in February 2012 for their role in what prosecutors claimed were al-Qaida inspired crimes.

Mohammed Shahjahan, 29, will now be sentenced to just over 17 years, while 22-year-old Usman Khan and Nazam Hussain, 27, will each serve 16 years.

Prosecutors said the three were part of a group of nine men planning attacks that could have led to serious casualties or fatalities.