As Forrest takes over at HCM's , he is replaced as publishing director of the outdoor leisure brands by Andrew Golby, who returns to Haymarket. Golby was previously publishing director of Haymarket's motorsport businesses before leaving last year for a job outside the company.
Patrick Fuller, publishing director of HCM's Motoring division, said: "PistonHeads has witnessed stellar growth in the past year and now has Haymarket's biggest online audience. Its rapidly expanding business development needs require the passionate and focused publishing management that Stuart is so well placed to provide."
As well as his duties overseeing Pistonheads, Forrest will continue as publishing director of the Classic & Sports Car brand, which will also get significant online development this autumn.
Bob McDowell, strategy and planning director of HCM's Leisure division, said: "Stuart has played a crucial role in a period of amazing development for Haymarket's 'outdoor leisure' brands.
"Under his stewardship, over the past 16 months the bedrock brands of Practical Caravan and Practical Motorhome have been augmented with three online acquisitions -- Caravan Sitefinder, RightCaravan4U, and RightMotorhome4U. This summer, the Practical Caravan and Practical Motorhome websites will get a complete overhaul."
Kevin Costello, managing director of Haymarket Consumer Media, said: "Andrew's background as a journalist of the highest calibre and a publishing director who demonstrated innovative and passionate leadership of his brands makes him an ideal choice of publishing director for this exciting portfolio. His is a very welcome return."
The changes will be effective from July 1 2008.