PROVISIONAL Airport Authority chief Hank Townsend is upbeat about the prospects of Joint Liaison Group discussions on the financing of Hongkong's new airport reopening soon, now that Sino-British talks have resumed. ''The re-starting of Sino-British talks is a positive sign,'' he said yesterday, following a speech to the Hongkong General Chamber of Commerce. He said: ''Hopefully, this will include a reopening of the Joint Liaison Group discussions on the airport, which we would welcome. ''I feel very confident that our friends in the Hongkong Government are concentrating on this aspect.'' Investors have also been optimistic this week that a solution to the Chek Lap Kok financing could finally be forthcoming, sending stocks to new heights. Share buyers were encouraged by speculation that Chinese negotiators might be willing to separate the economic issues from political ones. Beijing has insisted on linking airport financing with Governor Chris Patten's electoral reform programme. Mr Townsend said the PAA was in a good position to accelerate work as soon as approval for the funding was granted. While he conceded it was difficult under the current circumstances to give a date for the completion of the airport, he strongly rejected claims that 2000 was now more realistic than 1997. Continuing his upbeat mood, Mr Townsend said he thought morale among PAA staff was ''quite excellent'', despite having no guarantee they would be paid after June 30. The Governmment is expected to ask legislators for a further $1 billion to keep the PAA running through to March 1994. The money would maintain the PAA's operations for another nine months from June 30, including consultancy fees and wages.