The OFT is investigating 16 tenders submitted by Interserve's project services division between 2000 and 2005

Interserve is the latest company to admit it is being investigated by the Office of Fair Trading.

In a statement to the stock exchange today the company said that it was in correspondence with the OFT regarding 16 tenders submitted between 2000 and 2005.

It said: “The tenders relate to part of the regional building division of the project services business and represent a very small proportion of the bidding activity of the division during the period”.

It is the latest in a string of construction companies to admit they are under investigation.

Rok and Galliford Try yesterday announced that they were being investigated by the OFT and last Friday Kier said that it had been contacted by the OFT.

Last year Morgan Sindall and Carillion were the first to admit they were under investigation.

The OFT investigation into the construction industry has been running for more than two years and has seen 57 offices raided by inspectors. The investigation is looking into cover pricing in the industry, but it is not known whether it is confined to a particular sector or area of the country.

Any business found to have been partaking in cartel activity can be fined up to 10% of their global turnover, and in extreme cases directors can face up to five years in jail.