Exhibit 99.1
Magellan Petroleum Announces ASX Listing and Extension of Exchange Offer
Hartford, Conn., April 21, 2006 Magellan Petroleum
Corporation (Nasdaq: MPET) (Magellan) announced that (1)
the Company has extended for an additional three weeks, until May 12, 2006, its ongoing exchange
offer to acquire all of the ordinary shares of Magellan Petroleum Australia Limited (MPAL) that
it does not currently own (the Exchange Offer); (2) the Companys relevant interest in MPAL
shares has increased to 85.23%; and (3) the Company expects to be admitted to the Official List of
the Australian Stock Exchange (ASX) and its common stock (represented by CDIs) to be quoted under
the ASX trading symbol MGN next week once final administrative matters are cleared with the ASX.
For further information, please contact Daniel Samela at (860) 293-2006.
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