A majority of economists now see the Bank of Japan expanding its stimulus as its next move, with a strengthening of the yen from Federal Reserve rate cuts seen as a key factor for triggering action, according to a Bloomberg survey.

While all 50 polled economists expect no policy change at the two-day meeting ending Thursday, 62 percent of them think the central bank will ramp up easing measures as its next step, compared with 48 percent in April, the survey showed.

Economists said that against a backdrop of economic weakness, a sharp strengthening of the yen after U.S. rate cuts would trigger action from the BOJ. They predicted the yen would strengthen to ¥105 if the Fed starts lowering rates and that it would need to hit ¥100 to trigger action. The dollar was trading at ¥108.3 on Friday afternoon.