During the same period, the pace at which suppliers registered with the service grew 21 per cent faster in the three months to September this year than in the previous quarter with the total on the database now more than 20,000.
Almost 50 new client organisations switched their pre-qualification processes to Constructionline in the third quarter of this year, including South Tyneside Council, the London Borough of Haringey and Mansell Build.
The service - which is operated under licence from the Department of Business Innovation and Skills (BIS) by Capita - also reported a rise in the number of private sector contractors using its procurement tools to source smaller suppliers.
The figures came from its latest quarterly usage report.
Philip Prince, a director from Constructionline, said that the need for public sector clients to deliver efficiency savings and the downward pressure on tender prices from major contractors meant the service's footprint in UK construction has continued to grow.
"Faced with significant cuts to their capital projects, public sector organisations need to deliver schemes and maintenance more efficiently, and that starts with cutting out waste from the pre-qualification process.
"Equally, major contractors want to align their assessment procedures with those of their clients while reducing administrative costs. While conditions remain tough for the construction industry and its client base, our service can act as a vital procurement tool.
"As the number of buying organisations that use Constructionline continue to grow, so too do the opportunities for work and this has helped us pass a significant milestone in our history of having more than 20,000 contractors and consultants on Constructionline."