In court papers, Dreier LLP says Regan reneged on a retainer agreement she signed and then fired the law firm "in a transparent and calculated effort to avoid paying petitioners the agreed upon fee."

After Dreier prepared and filed the lawsuit, court papers say, Regan hired Los Angeles lawyer Bertram Fields to negotiate a settlement with HarperCollins. The terms were not disclosed.

After the settlement was final, Regan fired Dreier and refused to pay the firm, court papers say.

The lawsuit names Fields as a defendant and accuses him of tortious interference with the business relationship between Dreier and Regan.