By Elliot Gulliver-Needham The number of AIM companies has fallen below 700 for the first time since 2001, new data has confirmed, as London’s junior market has been battered by speculation that a key tax relief for AIM shares may be scrapped in this week’s Budget. Some 92 companies have delisted from AIM in the past year, with the total number of companies on the exchange sitting at just 695, according to new data from UHY Hacker Young. Shares on the junior market currently enjoy an inheritance tax break if they have been held for at least two years, but Chancellor Rachel Reeves has reportedl…