By Joshua Schneyer

NEW YORK (Reuters) - Sue Ann Arnall, the ex-wife of Oklahoma oil magnate Harold Hamm, vowed on Monday to press on with an appeal of her divorce case, even after she cashed a $975 million check from him.

In November, an Oklahoma court ordered the Continental Resources Inc chief executive to pay his ex-wife about $1 billion in cash and assets when the couple divorced after a 26-year marriage. The check for $975 million, which Arnall cashed last week, represented the entire balance owed by Hamm, according to the court's decision.

Arnall has appealed the case in the Oklahoma Supreme Court, claiming the earlier ruling allowed Hamm to keep the vast majority of a marital estate worth up to $18 billion.

"I will not dismiss my appeal and do not feel that my right to appeal should be denied because I have accepted, in the interim, a small portion of the estate that we built over more than two decades," Arnall said in a statement through her lawyers.

Responding to the news, Hamm filed a request with Oklahoma's Supreme Court seeking to get Arnall's appeal tossed out on the grounds she has already accepted the benefits of the earlier ruling.

"The Oklahoma state law is clear that the acceptance of the benefits nullifies her appeal," said Michael Burrage, one of Hamm's lawyers.

He called Arnall's appeal after accepting Hamm's payment "a classic case of wanting her cake and eating it too."

Last week, another of Hamm's lawyers, Craig Box, said Arnall's deposit of the oil man's check in an Oklahoma City bank was likely to end her case.

The Hamm divorce has been proceeding since 2012, and the November ruling was among the largest settlements for a U.S. divorce.

Last month, Hamm also pledged to appeal the decision after a sharp fall in oil prices cut billions from his personal fortune. The earlier court ruling allowed Hamm to retain his 68 percent stake in Continental.

(Reporting by Joshua Schneyer; Editing by Marguerita Choy and Andre Grenon)