FleetBoston Financial's energy and utilities group arranged a $1-billion revolving credit facility for Tosco Corp. (NYSE: TOS), Old Greenwich, Conn., a $250-million increase from the $750 million facility that Fleet completed for the independent refiner-marketer in February. Tosco plans to use funds from the revolve for general corporate and working capital requirements as well as for the acquisitions of Equilon Corp.'s Wood River refinery in Illinois and BP's Alliance refinery in Louisiana. Royal Bank of Canada and PNC Bank acted as syndication and documentation agents, respectively, in the transaction. Fleet Securities Inc. acted as lead arranger on the successful syndication of the transaction; 30 other banks participated. Germany's Commerzbank AG will provide $672 million in 10-year loans to Tyumen Oil Co., one of Russia's four largest oil entities. The package is the largest ever guaranteed by the Export-Import Bank of the United States to a Russian or Soviet company. Halliburton Co. (NYSE: HAL) will use $292 million of the loans that are aimed at stopping the decline and maintaining production of the portion of Siberia's giant Samotlor Field that Tyumen Oil controls, which produces 320,000 barrels of crude oil per day. The Dallas-based oilfield service and engineering and construction company will use an additional $93 million in other, unsecured, loans for the project. Tyumen Oil will use U.S. equipment and services, with U.S. and Russian labor. Commerzbank's New York branch is lending the money for the oilfield project. Tyumen Oil will use another $217 million in loans, which is scheduled to be guaranteed in October, to upgrade its Ryazan refinery, 120 miles southeast of Moscow, with help from ABB Lummus Global of Bloomfield, N.J. An additional $70 million in financing for the Ryazan project will come from other, unsecured sources. OMI Corp. (NYSE: OMM), Stamford, Conn., will receive $310 million of refinancing from a group of banks led by Christiania Bank og Kreditkasse. The international tanker owner-operator will use the money to refinance its existing bank debt and finance the costs of constructing two new vessels scheduled for delivery in September and November. Closing of the five-year financing is expected in early October. Triton Energy Ltd. (NYSE: OIL), Dallas, intends to sell $300 million of senior notes to qualified institutional investors in the United States and non-U.S. investors outside the United States. The Dallas-based overseas producer intends to use the proceeds to refinance its $200 million of 8.75% senior notes due 2002, as well as for capital expenditures and other general corporate purposes.