power broker

plural power brokers · alternative power-broker

1. A person or group having the ability to influence important decisions, especially in public policy, politics, and business.

   The Qatar government, which runs the QIA, will become a major power-broker in determining the future of the London exchange.

   2007 September 16, Louise Armitstead, “Qataris to seal bid for Nasdaq’s LSE stake”, in The Sunday Times, UK

   2 more examples

   In France, a near-revolution by students and workers came close to toppling Charles de Gaulle in May; its economic aftermath in November almost certainly discredited forever Gaullism's vaunted role as the power broker of Europe.

   1969 January 3, “Men of the Year”, in Time

   Gen Ali Murtopo—vice chairman of Indonesia's Supreme Advisory Council, former information minister, a major power broker in and out of the army—declared after a meeting with the president that the killings were justified.

   1988, Lewis B. Ware et al., Low-Intensity Conflict in the Third World,, Air Univ. Press, →ISBN, page 139