The World Health Organisation said an agreement has been reached on sharing flu virus samples, hammered out after intense negotiations by a group on preparations for flu pandemics.

The deal came four years after a working group comprised of representatives of member states was formed. It met this past week in Geneva with the goal of reaching a final accord.

"They reached an accord this morning (Saturday) after a night of intense discussions," WHO spokeswoman Fadela Chaib told AFP.

The deal not only involves sharing flu virus samples but also sharing the benefits which come from using certain samples, Chaib said.

The negotiations began in November 2007 after the appearance of the bird flu virus which triggered worldwide fear.

The accord will be presented to the next WHO general assembly in May.

The head of working group, Mexico's ambassador Juan Jose Gomez Camacho said earlier this week that despite the experience of the H1N1 swine flu pandemic in 2009, the world was still not properly armed against flu crises.

"The world is not prepared, it is not ready to face pandemics in an effective way," said Camacho.

He stressed that it was necessary to increase production capacity for vaccines and the means to distribute them, especially in the developing world, and to ensure that the vaccines are affordable.