A US judge is expected to rule this week on whether the owner of the World Trade Center can seek multi-billion dollar damages from the airlines whose planes crashed into into the Twin Towers on September 11, 2001, court officials said Tuesday.

District Judge Alvin Hellerstein, who has taken charge of most of the legal cases arising from the 9/11 attacks, has to decide whether World Trade Center Properties can pursue the owners of United Airlines and American Airlines for compensation on top of the four billion dollars the company has already collected from its own insurers.

Lawyers for the airlines argue that WTC Properties' insurers have already covered the same losses the company, owned by developer Larry Silverstein, is seeking to recover from them.

The judge has to decide whether any losses that could be ascribed to the airlines are in a different category to those that have already been covered.

If he does, Silverstein will then have to initiate separate proceedings aimed at proving that the airlines were liable for their planes being hijacked -- a case which would effectively put the whole pre 9/11 aviation security system on trial.

Hellerstein had originally anticipated the trial concluding on Wednesday and had indicated that he would deliver a ruling immediately after hearing concluding arguments. But court officials said Tuesday that the hearing was likely to run into Thursday at least.