The board of directors for Swiss-based oil refiner Petroplus announced on Tuesday that it plans to file for insolvency in Switzerland after talks with lenders failed . . . Petroplus had been Europe’s largest independent refiner . . . banks froze credit lines of almost $1 billion earlier this month, which prevented the company from supplying its five refineries with crude oil . . . Petroplus refineries had had a total daily capacity of 667,000 barrels . . . stock in Petroplus had lost 99 percent of its value since 2007 . . . Petroplus closed its refineries in France, Belgium, and Switzerland last month and announced last week that it was looking for buyers, however it had continued to operate its plants in the UK and Germany until this week . . . Standard and Poor’s had cut Petroplus credit rating for the second time on January 17 . . . the EU oil embargo on Iran could be the last straw for Petroplus . . . excess capacity and the European debt crisis is making it difficult for European oil refineries due to a decreasing demand for fuel . . . the economic outlook for oil refineries in Europe is expected to remain very bleak for the next twenty years . . . the sudden closure of the French, Belgian, Swiss, German and British refineries will be an additional blow to the already weak European economy.