Okla. Stat. tit. 22, § 22-352: Regular term - Extension

A. The regular term of a multicounty grand jury shall be

eighteen (18) months unless an order for discharge is entered

earlier:

1. by the court after the multicounty grand jury determines by

majority vote that its business is completed; or

2. by the court, on its own motion or on the motion of the

Attorney General, upon a determination that termination is in the

public interest.

B. The regular term of a multicounty grand jury may be extended

by the presiding judge for a specified time period upon a verified

petition by the Attorney General stating that an extension is

necessary to conclude a grand jury inquiry begun prior to the

expiration of the regular term. No jury so extended shall serve for

more than twenty-four (24) months, unless permission is granted by

the Supreme Court.