Talks between haulage firms contracted to Shell and tanker drivers, who began a strike on Friday, have resumed in an attempt to resolve their pay dispute.
Talks between haulage firms contracted to Shell and tanker drivers, who began a strike on Friday, have ended without a deal to end their pay dispute.
By Monday, the strike had affected 249 Shell outlets, and more than 600 of all the 8,700 petrol stations in the UK had run out of unleaded and diesel fuels.
The discussions are set to resume on Tuesday, with drivers threatening a second four-day stoppage next weekend if an agreement cannot be reached.
Drivers say they will hold a second four-day stoppage next weekend if an agreement cannot be reached.
Unite, the union representing the drivers, called the talks "helpful".
In Scotland, drivers working for other firms have also joined picket lines.
The current strike and picket lines have affected petrol stations across the UK, with some running out of fuel.
At the Grangemouth fuel depot, drivers working for other companies walked out and joined the Shell drivers' picket line, reported BBC Scotland transport correspondent Louise Batchelor.
The strike, which started on Friday and is due to finish at 0600 BST on Tuesday, has affected 249 Shell outlets, and more than 600 of all the 8,700 petrol stations in the UK had run out of unleaded and diesel fuels.
The drivers said the action was taken after hearing that 11 drivers employed by Scottish Fuels had been suspended for refusing to cross the picket line.
Meanwhile, the union Unite says it is optimistic about making progress during the talks with Shell.
Bernie Holloway, a director at Hoyer UK - one of the haulage firms affected - told the BBC he was glad that the two sides were talking again.
But he added: "I don't think we should kid ourselves there's a lot of work to be done, but we're hopeful and I'm sure that Unite and ourselves will be giving everything that we can to try and get this issue resolved."
The strike, affecting England, Wales and Scotland, began on Friday when the earlier talks over pay broke down.
The workers are not due to return to work until 0600 BST on Tuesday.
They have mounted picket lines at 14 terminals and fuel sites across the UK, including Shell's Stanlow Oil Refinery in Ellesmere Port and the Texaco plant at Pembroke Dock, Pembrokeshire.
Tanker drivers from companies not involved the dispute have joined Shell drivers' at the picket line.
News that 11 drivers employed by Scottish Fuels had been suspended for failing to cross the picket line, prompted further drivers to strike at Grangemouth.
Shell runs 10% of the country's fuel stations, but industry sources suggest its market share could be as much as 17%.
Affected stations
Cardiff, Cornwall and parts of London and the West Midlands have been badly hit by petrol stations running dry.
By Monday lunchtime, 616 petrol stations out of 8,700 in England, Scotland and Wales were out of standard fuels, the Department for Business, Enterprise and Regulatory Reform said.
This was lower than the 647 stations affected at the end of Sunday.
Drivers queue for petrol in the South West
Shell said shortages had affected one or more fuel grades at approximately 249 of its sites.
The BBC's Martin Shankleman said the fact that talks had been resumed were grounds for fresh optimism.
Union officials have maintained informal contact with managers from the two haulage firms Hoyer UK and Suckling Transport, which are contracted to Shell.
The haulage companies have said unions rejected a pay offer taking the drivers' average salary to £41,500 by January 2009.
THE SHELL PAY STRIKE The striking drivers work for two companies, Hoyer UK and Suckling Transport, contracted to ShellIndustrial action began when pay talks broke down this weekThe companies say unions rejected a pay offer taking the drivers' average salary to £41,500 by January 2009 But the Unite union says the offer would have increased salaries from just under £32,000 to £36,000The drivers are planning a second four-day stoppage next week if the dispute is not settled Rush to pumps is a trickleIs your area affected?
However, Unite says the offer would have increased salaries from just under £32,000 to £36,000.
The union also says it is in dispute with Shell because the oil giant dictates the structure and price of the tanker contracts, and therefore has the financial might and influence to affect the ultimate pay levels.
Len McCluskey, assistant general secretary of Unite, said: "We're hoping and we'll be working hard to try and conclude a satisfactory resolution to the dispute."
Earlier, James Smith, chairman of Shell UK, welcomed news that talks would start again.
"I think what everyone hopes for is a good and fair settlement - and let's hope that's what we see," he said.
Business Secretary John Hutton said the negotiations were an encouraging step forward.
He added: "I hope it is possible for the two sides to reach an agreement so as to avoid any repetition of this weekend's disruption."
