Talks to save the latest round of World Trade Organization negotiations apparently collapsed on Monday, leaving the future of a global trade agreement in doubt.

Following a meeting Sunday of Group of Six representatives -- the European Union, the United States, Japan, India, Brazil and Australia -- Reuters quoted a "well-placed trade diplomat" as saying, "The G6 talks have collapsed. It's not immediately evident what options are available other than suspension [of the Doha Round of negotiations]." The diplomat said there would be a full meeting of the 149-member WTO later in the day to decide the next steps to take.

United States Trade Representative Susan Schwab said on Monday that Washington would continue to seek a successful outcome to Doha, but had to be sure a deal resulted in a real opening-up of trade in other markets.

Schwab told journalists that a marathon negotiating session on Sunday yielded no progress on the question of increased market access for agricultural products. "We won't give up... [but] unfortunately it became clear that a 'Doha Light' is the preferred option of some," she said.

If the latest of several 'last-ditch' attempts fails on Monday, it could leave the WTO without enough time to complete all the complex details of free-trade treaty by the end of the year.

The year-end deadline for concluding the talks, which were launched in the Qatari capital in late 2001, is dictated by the 2007 expiration of special U.S. presidential powers to negotiate on trade.