* Greybull Capital tipped to buy the struggling refinery
* Plant and retail petrol stations would continue operating
By Ron Bousso and Simon Falush
LONDON, March 18 (Reuters) - Murphy Oil is in advanced talks to sell its Milford Haven refinery in Wales to a low-profile private equity fund that will continue operating the struggling plant, sources familiar with the situation said on Tuesday.
Arkansas-based Murphy Oil has been trying to sell the 135,000 barrels-per-day plant and its Murco petrol stations for around four years. But buyers who were willing to keep it running have proved elusive as European refineries fight for survival due to failing demand.
A deal is now moving closer with London-based Greybull Capital after it had agreed to fund a major planned maintenance at the plant within the next 18 months, sources said.
"There is a form of agreement pending finance," said a source close to the negotiations.
The maintenance turnaround at Milford Haven was expected to cost less than $75 million, the source said. The full cost of the deal was unclear.
The source said that a commitment to fund the turnaround was vital to prevent any buyer from running the plant for a short time before closing it down to sell assets, or demand a government bailout.
Greybull has in the past focused on financing deals to buy struggling British high street chains such as the ultimately doomed electrical goods outlet Comet. It declined to comment on the Milford Haven discussions.
Greybull would probably need to partner with either a commodity trading house or a bank with trading capabilities in order to secure the funding for the deal to keep the 450 employees in place.
"They are trying to raise the money in order to keep the work force in place," an industry source said.
A spokeswoman for Murco, the Murphy Oil subsidiary that operates the refinery, confirmed talks for the sale of the refinery were coming closer to a conclusion.
"Discussions with regard to the sale of the Murco UK business by its U.S. parent, Murphy Oil Corporation, are ongoing and are at an advanced stage," Emma Murphy said in an email.
Murco's 400 petrol stations across the country would also be part of the deal.
"The buyers will purchase the Murco name and the supply system which will continue to supply the Murco petrol stations," the industry source said.
Murco also operates three storage and distribution terminals in Britain which are supplied by rail from the refinery and handle around 2 million tonnes of oil product a year, according to the company's website.
The Welsh plant, like other British and European refineries, has struggled in recent years due to weak demand in the region and in its U.S East Coast export market, as well as growing competition from U.S., Russian and Asian plants - factors which have hammered margins.
India's Essar Energy said last month it will shutter one third of its production capacity at Britain's second-largest oil refinery Stanlow.
Last year the Grangemouth refinery in Scotland was brought to the brink of closure following a bitter industrial dispute, after owner Ineos said it needed to slash costs to keep it viable.
This followed the closure of the Coryton plant owned by bankrupt Petroplus which closed in 2012.