UPDATE 1-Lockheed, Pentagon ink $4.7 bln deal for 8th batch of F-35 fighters

WASHINGTON, Nov 21 (Reuters) - The Pentagon said on Friday it had awarded Lockheed Martin Corp a contract valued at $4.7 billion for an eighth batch of F-35 fighter jets, marking a drop in cost per plane of 3.5 percent from the last contract, and a 57 percent reduction from the first batch.