<PAGE>
===============================================================================
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
SCHEDULE 14A
Proxy Statement Pursuant to Section 14(a) of the Securities
Exchange Act of 1934
Filed by the Registrant [X]
Filed by a Party other than the Registrant [_]
Check the appropriate box:
[_] Preliminary Proxy Statement
[_] CONFIDENTIAL, FOR USE OF THE
COMMISSION ONLY (AS PERMITTED BY
RULE 14A-6(E)(2))
[_] Definitive Proxy Statement
[X] Definitive Additional Materials
[_] Soliciting Material Pursuant to (S) 240.14a-11(c) or (S) 240.14a-12
Vastar Resources, Inc.
--------------------------------------------------------------------------------
(Name of Registrant as Specified In Its Charter)
--------------------------------------------------------------------------------
(Name of Person(s) Filing Proxy Statement, if other than the Registrant)
Payment of Filing Fee (Check the appropriate box):
[x] No fee required.
[_] Fee computed on table below per Exchange Act Rules 14a-6(i)(4) and 0-11.
(1) Title of each class of securities to which transaction applies:
-------------------------------------------------------------------------
(2) Aggregate number of securities to which transaction applies:
-------------------------------------------------------------------------
(3) Per unit price or other underlying value of transaction computed
pursuant to Exchange Act Rule 0-11 (set forth the amount on which
the filing fee is calculated and state how it was determined):
-------------------------------------------------------------------------
(4) Proposed maximum aggregate value of transaction:
-------------------------------------------------------------------------
(5) Total fee paid:
-------------------------------------------------------------------------
[_] Fee paid previously with preliminary materials.
[_] Check box if any part of the fee is offset as provided by Exchange
Act Rule 0-11(a)(2) and identify the filing for which the offsetting fee
was paid previously. Identify the previous filing by registration statement
number, or the Form or Schedule and the date of its filing.
(1) Amount Previously Paid:
-------------------------------------------------------------------------
(2) Form, Schedule or Registration Statement No.:
-------------------------------------------------------------------------
(3) Filing Party:
-------------------------------------------------------------------------
(4) Date Filed:
-------------------------------------------------------------------------
<PAGE>
NR00-18
August 17, 2000
FOR IMMEDIATE RELEASE
VASTAR SETS SEPT. 15 AS DATE OF SPECIAL SHAREHOLDERS MEETING
TO CONSIDER PROPOSED MERGER WITH BP
Houston, TX -- Vastar Resources, Inc. (NYSE: VRI) today announced that its board
of directors has set a date of Sept. 15, 2000 for a special meeting of
shareholders to vote on the company's proposed merger with BP (NYSE: BP).
Vastar shareholders are being asked to vote on a merger in which BP would
acquire the remaining 18.2 percent of Vastar stock not currently owned by BP.
If the merger is completed, Vastar shareholders, other than BP, will receive $83
for each share of Vastar common stock.
Only shareholders of record - those who owned shares at the close of
business on July 28, 2000 - will be eligible to vote at the meeting, which will
begin at 9 a.m. in the main conference room at Vastar's headquarters at 15375
Memorial Drive in Houston.
Vastar further announced that earlier today it filed a definitive proxy
statement on Schedule 14A with the U.S. Securities and Exchange Commission
relating to the matter to be voted on at the meeting, and today will also mail
the proxy statement to shareholders of record.
Vastar Resources, Inc., headquartered in Houston, Texas, finds, develops
and produces natural gas and liquid hydrocarbons. The company is currently
active in more than 100 producing fields,
1
<PAGE>
with production in the Gulf of Mexico shelf and deepwater, Gulf Coast, Rocky
Mountains and Mid-Continent areas. Additional information on Vastar is available
on the company's website at.www.vastar.com.
###
Contacts: James Bartlett (281) 584-3448 (media)
Ellen DeSanctis (281) 584-3477 (financial)
Vastar shareholders are strongly advised to read the company's proxy statement
relating to the shareholder vote as it contains important information.
Shareholders can obtain the proxy statement and other filed documents for free
at the Internet website maintained by the Securities and Exchange Commission at
www.sec.gov. In addition, Vastar Resources, Inc. will mail the proxy statement
today, Aug. 17, 2000, to each shareholder of record on July 28, 2000 and will
also make additional copies of the proxy statement available for free to
Vastar's shareholders. Please direct your request for the proxy statement to
Ellen DeSanctis, manager of Investor Relations and Corporate Communications,
Vastar Resources, Inc., 15375 Memorial Drive, Houston, Texas 77079, telephone
(281) 584-3477.
2
