Berkshire said it would acquire the remaining 20% of IMC International Metalworking it does not already own from the Wertheimer family. It had bought an 80% stake from the Wertheimers for $4 billion in 2006.
A dealer at a large bank said in anticipation of the deal billionaire the family had sold about $500 million in dollars in recent sessions.
The shekel was fixed at 3.5870 per dollar - its strongest level since September 2011 - from 3.5940 on Tuesday.
After the fixing, the shekel gained to 3.5750.
The Bank of Israel on Tuesday had bought an estimated $200 million of foreign currency to try and weaken the shekel. With exports comprising 40% of Israeli economic activity, the central bank has made it clear it will not allow a steep rise in the shekel.
On April 8, after dollar-shekel closed in on a rate of 3.59 the central bank intervened for the first time since July 2011.
A dealer at another bank said the market had expected another round of intervention on Tuesday.
"Everyone is waiting and getting long and they don't call," he said.
A stronger euro versus the dollar also aided the shekel's appreciation, dealers said.
The shekel has gained some 6% the past five months.