PARKER & PARSLEY 85-A LTD

Q: Sep 30 2001

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FY: Dec 31 2000

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2

4

4

Certification of termination of registration of a class of securities (Section 12(g))

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

Written communication about a business combination transaction (Rule 425)

PIONEER NATURAL RESOURCES CO

PIONEER NATURAL RESOURCES USA INC