Gazprom is a multinational energy corporation headquartered in the Lakhta Center in Saint Petersburg, Russia. As of 2019, with sales over USD$120 billion, it sits as the largest publicly-listed natural gas company in the world and the largest company in Russia by revenue.

 

In the 2019 Forbes Global 2000, Gazprom was ranked as the 40th largest company in the world. 

Gazprom was created in 1989. Gazprom is vertically integrated and is active in every area of the gas industry, including exploration and production, refining, transport, distribution and marketing, and power generation.

In 2018, Gazprom produced twelve percent of the global output of natural gas, producing 497.6 billion cubic meters of natural and associated gas and 15.9 million tonnes of gas condensate. 

According to en.wikipedia