AUSTIN (KXAN) — As soon as Russia began its invasion of Ukraine, companies around the world began announcing they were ending or curtailing their business in Russia.

At the same time, researchers at Yale University’s School of Management began tracking which companies were leaving, and which continued business as usual.

The Yale list includes more than 600 companies that have pulled out of Russia and gives them letter grades on how far they’ve gone in dissolving their business in the country.

The list includes eight of the Top 25 Fortune 500 companies identified by Austin’s Concordia University as being headquartered in Texas.

The Criteria

To earn an A grade, companies need to be “totally halting Russian engagements or completely exiting Russia.” Yale researchers refer to this as a “clean break – surgical removal, resection.”

B grades were given for “companies temporarily curtailing most or nearly all operations while keeping return options open.”

Companies scored a C if they “are scaling back some significant business operations, but continuing some others.”

Companies getting D grades are those that are holding off on new investment, while continuing current business in Russia.

An F was given out to companies continuing business as usual in Russia.

The List

American Airlines – A

The Fort Worth airline is the largest carrier on the Fortune 500 list, according to Fortune. Yale gave the carrier an A grade for no longer flying over Russian airspace and suspending its Russian partnerships.

ExxonMobile – A

With $236.4 billion in market value, Irving-based ExxonMobile is Texas’ second-most valuable company and No. 10 in the nation. It earned an A grade for ending its partnership with Rosneft, a state-controlled Russian oil and gas company.

Dell – B

The Round Rock company employs 158,000 people and produces some of the most-used computers in the world. It received a B grade for suspending all shipments to Russia.

Oracle – B

The Austin-based company recently relocated its headquarters from Silicon Valley in California. It earned a B for suspending all operations with Russia.

Valero Energy – B

The San Antonio-based company is “the largest independent petroleum refiner in the world and America’s largest renewable fuels producer,” according to Concordia. It got a B after suspending purchases of Russian oil.

Hewlett Packard – B

With nearly 60,000 employees, Houston-based Hewlett Packard is valued at just more than $20 billion. It scored a B for suspending all shipments to Russia.

Halliburton – C

The Houston-based company works with “oil and natural gas companies around the world to help them achieve greater efficiency and cost savings,” according to Concordia. It got a C for suspending future business in Russia while winding down current business.

Baker Hughes- D

The Houston company operates in more than 120 countries around the world, including Russia. Its D is for pausing new investments and development in the country.

Kimberly-Clark – D

The Irving-based company produces personal care products through multiple brands. It earned a D for committing to suspend new investment in Russia.