AN EMISSION-LINE REGION ASSOCIATED WITH 3C-273

We have observed an extended emission line region about 4 '' to the So uth-East of 3C 273 in the light of the lines [OII] lambda 372.8 nm and [OIII] lambda 500.7 nm, with an overall linear dimension of similar t o 20 x 10 kpc and a brightness of similar to 10(-18) W m(-2) in either line. HST images show the region to be split up into several knots. T he line intensity ratios and colors are consistent with W excitation f rom the QSO, but also with shock excitation due to a possible collisio n of the cloud with the gas of the host galaxy of 3C 273 at high veloc ity.