The Experian insolvency Index found 13% fewer large firms (501 or more employees) failed during July 2011 compared to July 2010.
The national rate of insolvencies increased with 0.10% of firms failing in July 2011, up from 0.08% in July 2010.
The insolvency rate is calculated by comparing the number of businesses that failed with the total business population in Great Britain.
Businesses employing 51-100 people experienced the biggest annual increase in insolvencies, with the proportion of businesses failing growing from 0.15% in July 2010 to 0.22% in July this year.
Firms with 11-25 employees saw the highest percentage of businesses fail in July 2011 (0.26% of the population).
The North West of England saw 0.14% of its firms fail, more than any other region. Scotland maintained the lowest insolvency rate with 0.07%, while Yorkshire maintained its July 2010 insolvency rate of 0.13%.
Max Firth, MD of Experian Business Information Services, said: "When a large company becomes insolvent it can create a domino effect in the surrounding economy, so the improvement in insolvency rates with firms with more than 500 employees is good news.
"However, this doesn't lessen the need for all organisations, regardless of their size or sector, to be mindful of the risks their customers, suppliers and partners can expose them to.
"It is vital that businesses fully understand the financial strength of those they do business with by checking their commercial credit score and late payment trends."