AN immigration tribunal is to consider for the third time whether two young girls were born in Hong Kong and therefore have the right to remain here, after a Court of Appeal ruling yesterday. Twice the High Court has found procedural improprieties with the tribunal and quashed its findings. But the Director of Immigration yesterday successfully appealed against the most recent High Court decision from Mr Justice Jones, who had ordered that the removal order be quashed because there was a breach of natural justice. Chan Choi-hung, seven, and Chan Choi-ping, six, are fighting to be allowed to stay with their three siblings, two of whom have been born during the litigation, and the eldest, nine, who was born in hospital in the territory. Their father, Chan Lam-choi, claims his wife, Tang Lin-tai, sneaked into Hong Kong, and he delivered the two girls in June 1986 and April 1987. He called two witnesses but the tribunal found he had not produced a single piece of evidence to substantiate his claim, which Mr Justice Jones said was ''astonishing'' and ''illogical''. Yesterday, Mr Justice Litton held that Mr Justice Jones had gone too far in quashing the removal order, a decision he was not asked to consider. All that was before him was the order dismissing the children's appeal against the removal order. He said the judge must have realised that the director was not a party before him, only the immigration tribunal was represented. As the judge had no jurisdiction to make the orders, the director's appeal must succeed. The court declined to make an order sought by Barrie Barlow, counsel for the children, requiring the immigration tribunal to be reconvened to consider the case again in the light of Mr Justice Jones' findings that the decision was illogical and could notstand. Mr Justice Litton pointed out the tribunal was not represented before them. Without criticising Mr Justice Jones, Mr Justice Litton said he was troubled by some of the expressions used in his judgment. Adjudicators were not lawyers and they were expected to use common sense. He pointed out that the two girls had been involved in litigation since early last year and the sooner it was resolved the better.