ISLAMABAD — Mohammad Zubair was on a dinner cruise in Thailand with Prime Minister Nawaz Sharif of Pakistan when he was offered the hardest job of his life: privatizing a huge chunk of the economy while fighting resistance from the opposition and trade unions.

When the prime minister left the table, a colleague of Mr. Zubair, a former IBM executive, rushed to his side.

“Are you mad?” he said. “Three privatization ministers have gone to jail and most have corruption cases hanging over their heads. Don’t take this job.”

But Pakistan’s new privatization minister is determined to find buyers for 68 public companies, most of them loss-making, including two gas companies, an oil company, about 10 banks, the national airline and power distribution companies — all within the next two years.