Olympic venues for the 2004 Athens Games are finally getting off the ground, after years of delays. About a third of the Olympic village (photo), the largest project under construction, has been built. A consortium of four Greek construction firms yesterday signed a 182-million-euro ($162.5 million) contract to build the second largest project, an equestrian center and racing track at Markopoulo, close to the new Athens airport. The firms are Avax subsidiary ETETH, J&P Hellas, GEK and K.I. Sarantopoulos.