Exhibit 99.1

Tesoro Completes Refinancing

    SAN ANTONIO--(BUSINESS WIRE)--April 21, 2003--Tesoro Petroleum
Corporation (NYSE:TSO) announced that it successfully completed the
refinancing of its senior secured credit facility.
    The company issued $375 million in 8 percent senior secured notes
and $200 million in senior secured term loans both maturing in 2008.
Tesoro also entered into a $650 million senior secured credit facility
that includes a letter of credit sub-limit of $400 million. The senior
secured credit facility, together with the net proceeds of the senior
secured notes and senior secured term loans, replaced the company's
previous $1.275 billion senior secured credit facility.
    As part of the refinancing, the company made an open market
repurchase of $25 million of its 9.625 percent senior subordinated
debt to take advantage of the lower interest rate on the new debt.
    "I am very pleased with the strong market demand we received for
this refinancing," said Bruce A. Smith, Chairman, President and CEO of
Tesoro. "The transaction was over-subscribed, we achieved lower
interest rates than expected and less restrictive financial
covenants."
    Highlights of the refinancing are as follows:

    --  The new senior secured credit facility with an aggregate
        maximum availability of $650 million and a letter of credit
        sub-limit of $400 million replaced the company's previous $225
        million revolving credit facility with a letter of credit
        sub-limit of only $150 million. The new senior secured credit
        facility consists of a $500 million revolving credit line and
        a $150 million term loan and is secured by substantially all
        of Tesoro's inventories, accounts receivable and cash. Final
        terms of the senior credit facility will be available after
        syndication is complete, which is expected to occur next
        month. Interest on the revolving credit line is initially
        calculated by using the London Interbank Offered Rate (LIBOR)
        plus 3.25 percent, but can go lower dependant upon excess
        availability under the facility . Facility borrowings at close
        were $321 million.

    --  $375 million of senior secured notes were issued at a discount
        with a coupon rate of 8 percent and a yield to maturity of
        8.25 percent. The senior secured notes have a 3-year no call
        period, after which they are callable with a call premium of 4
        percent in year four and at par in year five.

    --  The $200 million senior secured term loans have an interest
        rate of LIBOR plus 5.5 percent. Using current LIBOR rates, the
        total interest rate on the loan is 6.84 percent. The senior
        secured term loans have a 1-year no-call period, after which
        they are callable with a call premium of 3 percent in year
        two, 1 percent in year three and at par thereafter. Both the
        $375 million 8% senior secured notes and the $200 million
        senior secured loan are secured by the company's refineries,
        pipelines and terminals.

    --  Substantially improved financial covenants under the new
        senior secured credit facility are designed to provide
        continued availability, even in a lower margin environment.

    The company announced it expects its annual cash interest expense
to decrease due to the refinancing package that was announced today
although it will record a non-cash, pre-tax charge of $33 million
during the second quarter for the unamortized debt issuance costs
related to the company's previous financing.
    "This refinancing lowers our expected cash interest expense and
will also allow us to pay down debt in an expedited manner, when
compared to our old senior secured facility, due to the increased
sub-limit for letters of credit. The increased capacity to issue
letters of credit should enable us to lower our net working capital by
more than $100 million and apply the funds to debt retirement --
during the second quarter," added Smith.

    Tesoro Petroleum Corporation, a Fortune 500 Company, is an
independent refiner and marketer of petroleum products and provider of
marine logistics services. Tesoro operates six refineries in the
western United States with a combined capacity of nearly 560,000
barrels per day. Tesoro's retail marketing system includes
approximately 600 branded retail stations; of which over 200 are
company operated under the Tesoro(R) and Mirastar(R) brands.

    This news release contains certain statements that are
"forward-looking" statements within the meaning of Section 27A of the
Securities Act of 1933 and Section 21E of the Securities Exchange Act
of 1934. These forward-looking statements contain projections as to
the expected interest expense savings and potential debt reduction
through reduced working capital needs due to the recently completed
refinancing of the company's senior secured credit facility. Factors
which may cause actual results to differ from those forward-looking
statements include: changes in general economic conditions, worldwide
political conditions and war, disruptions due to equipment
interruptions or failure at Tesoro-operated or third-party facilities,
and other factors beyond Tesoro's control. For more information
concerning factors that could cause such differences, see Tesoro's
annual report on Form 10-K and other of Tesoro's reports filed with
the Securities and Exchange Commission. Tesoro undertakes no
obligation to publicly release the result of any revisions to any such
forward-looking statements that may be made to reflect events or
circumstances that occur, or which Tesoro becomes aware of, after the
date hereof.

    CONTACT: Tesoro Petroleum Corp., San Antonio
             Investors:
             John Robertson, 210/283-2687 (Investor Relations)
             or
             Media:
             Tara Ford, 210/283-2676 (Public Relations)