(Reuters) - The U.S. Treasury on Friday announced sweeping new sanctions against the Russian energy sector, including oil majors Gazprom Neft and Surgutneftegaz, to try to hinder Moscow in its war with Ukraine.

Britain also joined the sanctions against those two companies, the U.S. Treasury said.

The sanctions also target more than 180 vessels and dozens of oil traders, oilfield service providers, insurance companies and energy officials, according to the Treasury's Office of Foreign Assets Control (OFAC).

Following are some key entities and individuals affected:

RUSSIAN OIL MAJORS

Gazprom Neft;

Surgutneftegaz;

More than two dozen subsidiaries of Gazprom Neft and Surgutneftegaz, including Moscow Oil Refinery and entities based in Kazakhstan, Kyrgyzstan and Luxembourg.

RUSSIA'S SEABORNE OIL EXPORTS

Russia's state-owned shipping company and fleet operator Sovcomflot;

Two Russia-based maritime insurance providers: Ingosstrakh Insurance Company and Alfastrakhovanie Group, both previously sanctioned by the UK;

Sixty-nine vessels owned by Sovcomflot, including 54 oil and product tankers and four liquefied natural gas (LNG) tankers;

Two UAE-based ship managers that support Sovcomflot: Fornax Ship Management FZCO and Stream Ship Management FZCO;

One hundred and eighty-three vessels, largely oil tankers, that are part of the shadow fleet as well as oil tankers owned by Russia-based fleet operators;

Rosnefteflot, the marine transportation arm of the Russian oil company Rosneft.

Sovcomflot, Rosnefteflot, Gazpromneft Marine Bunker and other shipping companies listed in the new sanctions have been regular shippers of Russian oil to India.

OPAQUE TRADERS OF RUSSIAN OIL

Black Pearl Network, a major trader of Russian crude oil, including barrels priced above the $60 price cap. Since 2023, Black Pearl has likely sold more than $2 billion worth of Russian crude oil and oil products, according to OFAC;

UAE-based Conmar Maritime DMCC (Conmar), which is affiliated with Black Pearl, and a number of other UAE- and Hong Kong-based trading offices.

RUSSIAN ENERGY OFFICIALS

Yusuf Alekperov, the founder and owner of Russian oilfield services company Welltech and son of one of Lukoil's founders, Vagit Alekperov;

Aleksander Dyukov, CEO of Gazprom Neft;

Sergei Kudryashov, CEO of oil producer Zarubezhneft;

Nail Maganov, the head of oil producer Tatneft;

Vadim Vorobyev, CEO of Lukoil;

Vladimir Bogdanov, CEO of Surgutneftegaz.

(Reporting by Reuters; Editing by Kevin Liffey)