MIPIM: Turnover in the West End office investment market could tumble by 25% this year, agents at MIPIM have warned.

The high value of transactions seen in 2012 in the West End will not be repeated this year, said Julian Sandbach, director of West End investment at Jones Lang LaSalle.

He has forecast that revenue this year could fall to around £4bn, a drop of about a quarter on 2012 figures.

Sandbach said: "We will see a lot less stock on the market and that is because many investors are deciding to hold on to assets. Many continue to buy into the rental growth story and believe the value of their properties will rise."

Colliers International has calculated that just 16 West End deals have completed in the year to date, compared to around 30 in the first quarter of last year.

Dominic Amey, a director in Colliers' West End team, said: "Last year there was an unusually high number of transactions, but 2013 will see more property owners wanting to keep their buildings."

Amey added that the shortage of supply could result in increased competition from investors to buy what is available, leading to higher bidding.