At the World Economic Forum that is winding up Saturday at the Swiss resort of Davos, trade officials from several rich and developing countries held informal talks intended to boost the prospects of completing a new global trade liberalization accord by the end of this year.

The discussions on trade have been numerous and informal. Key developing countries have met among themselves, and there have been broader talks with policy-makers from Europe and the United States.

At issue is the Doha Development Round, a trade liberalization negotiation that was launched four years ago. The talks nearly collapsed two years ago, but have recently been revived. There are now hopes they could be successfully completed at a World Trade Organization meeting in Hong Kong in December.

Outgoing U.S. Trade Representative Robert Zoellick says a deal is possible, but not assured.  He said the major trading countries must play a constructive leadership role.

"This round will not be successful, unless the U.S. and EU continue to play that [leadership] role,? said Mr. Zoellick.  ?I wish Japan would play more of a role. But, this time, it is going to be fundamental that the bigger developing countries [such as] China, Brazil, India, South Africa, Egypt play a key role."

Mr. Zoellick says it is extremely difficult for 148 nations to reach unanimous agreement, as required by WTO rules.

French Finance Minister Herve Gaymard cautions that there are still difficulties over agricultural subsidies, which were a key stumbling block that contributed to the near collapse of the talks two years ago. Mr. Gaymard says the United States and Europe have not yet reached consensus, but WTO members promised last year to negotiate an end to trade distorting agricultural subsidies.

"To eliminate the export subsidies for agriculture in all countries, Europe, of course, but also the United States, and the other countries which have export subsidies, we will be very attentive about the coming negotiations to reach this goal by December in Hong Kong," he said.

A Brazilian official, who hosted one of the informal gatherings here in Davos, said developing countries agree that export subsidies should end. But, he added, they have not yet agreed on opening up their own agricultural markets.

Over the next few weeks there will be further discussions in Geneva and in India on how to complete the Doha round.