(Reuters) - Indian billionaire Gautam Adani oversees a sprawling conglomerate with activities spanning construction of airports to supply of electricity and the sale of cooking oil.

U.S. authorities have accused Adani, his nephew and executive director Sagar Adani and managing director of Adani Green, Vneet S. Jaain, of being part of a scheme to pay bribes of $265 million to secure Indian power supply contracts, and misleading U.S. investors during fund raises there.

The group has called the allegations baseless.

Here are key details of the Adani Group's businesses:

** Energy: It mines thermal coal and produces power through its utilities firm Adani Power, which is transmitted via Adani Energy Solutions.

The renewable energy arm of the ports-to-power conglomerate is Adani Green Energy, which is at the center of the U.S. indictment. It focuses on solar, wind and hybrid power generation and has a presence in a dozen Indian states.

Adani Total Gas, which distributes piped natural gas, is run in a partnership with TotalEnergies.

** Airports: Since entering the space in 2019, the group runs airports in cities from Mumbai, the commercial capital, to the tourist city of Jaipur and southern Thiruvananthapuram, through its flagship firm, Adani Enterprises.

The flagship also has a presence in roadways, real estate and infrastructure.

** Edible oils and food: The group's joint venture with Singapore's Wilmar International makes edible oils and packaged food items such as fragrant basmati rice, wheat flour and sugar under the Adani Wilmar banner.

** Port operations: Adani Ports, India's top private operator by volume, manages 13 domestic ports, including the country's busiest private port, Mundra in the western state of Gujarat.

Outside India, Adani Ports owns a stake of 70% in Israel's port of Haifa and 51% in Sri Lanka's Colombo port.

** Cement: The group entered the industry in 2022, inking its biggest-ever deal in the space by acquiring Holcim AG's stake in Ambuja Cements and ACC. It has been on an acquisition spree since in its bid to topple India's top cement maker, UltraTech Cement.

** Media: Adani entered India's media industry by acquiring a majority stake in Quintillion Business Media, a financial news digital media platform, in 2022. Afterwards, it strengthened its hold in the space by striking deals with news broadcaster NDTV in 2022 and news agency IANS in 2023.

It also builds and runs data centres nationwide.

** Defence and aerospace: One of the few private players in a state-dominated weapons sector, the group supplies domestically made weapons to Indian forces. In 2018, it signed a supply deal with Israel's Elbit Systems.