LONDON and WASHINGTON — The South Korean defense procurement agency will announce Jan. 12 that it plans to buy up to 36 AH-X attack helicopters, kicking off a major competition.

Bids are due May 10.

Likely entrants include the Boeing AH-64D Block III Apache, now preparing for initial operational test and evaluation in March for the U.S. Army. Bell also is planning to propose its AH-1Z “Zulu,” which is now on its first deployment for the U.S. Marine Corps. Also in the running are the Eurocopter Tiger and the AgustaWestland A129, likely in the T129 ATAK configuration in development for Turkey.

This competition will be the first international bid for Bell’s AH-1Z, and, thus, its first attempt to go head-to-head against its U.S.-made competitor, the Apache.

Also this year, India is expected to solidify its contract with Boeing for 22 Apache Block IIIs to satisfy its attack helicopter requirement.