LONDON (Bloomberg) - Tanker drivers for Royal Dutch Shell plc., who deliver gasoline to 10 percent of the UK's filling stations, will start a four-day strike over pay today after talks with their employers broke down.

The Unite union, representing 641 drivers, failed to reach agreement with Shell subcontractors Hoyer GmbH Internationale and Suckling Transport Ltd., union spokeswoman Pauline Doyle said in a telephone interview yesterday.

Shell, which is not involved in the pay negotiations, said supplies to its filling stations would suffer and that it has teams working to ensure that as much fuel as possible gets through to customers.

"If the industrial action goes ahead, regrettably it is inevitable that it will have a significant impact on our petrol stations," spokeswoman Olga Gorodilina said in a telephone interview.

The company urged the two sides to continue their talks. The union's assistant secretary-general, Len McCluskey, said in a statement that provisions have been made for police and other emergency services.

The drivers are seeking a 13.2 percent pay increase. The union says its workers earn the same now for a 48-hour work-week as they got for a 37-hour week in 1992.

The strike, which is due to last until the evening of June 16, will affect 14 terminals across the UK, Unite said. It will also affect supplies to some factories and airports.

Prime Minister Gordon Brown urged people not to engage in panic buying.

"We are determined to do everything we can to ensure the supply of fuel to people," Mr. Brown said at his monthly news conference.