The American company for the exploration and production of natural gas BARRETT RESOURCES (turnover $376 million in 2000 with 200 employed), rejected the unsolicited offer of acquisition made by ROYAL DUTCH SHELL for the sum of $1.8 billion. It seeks to sell for more, explicitly inviting the Anglo-Dutch group to make a bigger offer. According to the British press, ROYAL DUTCH SHELL would now be willing to disburse around $2.5 billion to acquire BARRETT RESOURCES.