DUBAI, United Arab Emirates—Ahmed Zaki Yamani, a long-serving oil minister in Saudi Arabia who led the kingdom through the 1973 oil crisis that shattered the West and once found himself held hostage by the assassin Carlos the Jackal, died Tuesday in London. He was 90. Saudi state television reported his death, without offering a cause. It said he would be buried in the Muslim holy city of Mecca. Known for his Western-style business suits and soft-spoken, measured tones, Yamani helped Saudi Arabia command a dominating presence in the Organization of the Petroleum Exporting Countries from its birth. The kingdom remains a heavyweight in the group even today and its decisions ripple through the oil industry, affecting prices from the barrel down to the gasoline pump. “To the global oil industry, to politicians and senior civil servants, to journalists and to the world at large, Yamani became the representative, and indeed …