Bridgestone Corp. President Shigeo Watanabe on Tuesday said that the firm's move to end almost 100 years of supplying tires to Ford Motor Co. was a "wrenching decision."

The move came a day after its U.S. unit announced the action following a row over a massive tire recall.

The unit, Bridgestone/Firestone, has recalled millions of its tires installed on Ford Explorer sport utility vehicles since August.

"Although we have repeatedly asked Ford to make joint efforts to identify the cause of the accidents (involving the Firestone tires and Explorers), Ford has not complied with our request," Watanabe told a news conference.

"So we had to make that wrenching decision," he added.

The tires annually supplied to Ford accounted for 3 percent to 4 percent of the subsidiary's overall sales on a value basis, and 2 percent of sales by the Bridgestone group.

"Although the risk that our transactions with the Ford group, including Mazda Motor Corp., will be completely ended is not nonexistent, it would not be fatal (to Bridgestone group companies)," Watanabe said.

Ford has suggested it may recall more of its vehicles equipped with Firestone tires in addition to the 6.5 million Firestone ATX and Wilderness ATX tires recalled by the U.S. unit last summer.

The recall followed more than 100 road deaths in the United States allegedly caused by tread peeling off the tires.

Responding to the Ford suggestion of an additional tire recall, Watanabe said, "We estimate they are planning to recall an additional 11 million (Firestone) tires."

"A decision on whether to recall them or not is not an issue that Ford should determine," he added.

Ford has spent more than $500 million on tire replacements and related costs since last August, industry sources said.