McGraw Hill has hired Morgan Stanley to assist with the sale process, the people said this week. J.D. Power, best known for its car quality and reliability ratings, could be worth as much as $1 billion, one of the people added.

J.D. Power may appeal to private equity firms as well as companies in the automotive sector such as Cox Enterprises, which owns Autotrader, an online car marketplace, and Manheim Auctions, one of the largest car auction companies.

The sources asked not to be identified because the sale process is confidential. Representatives from McGraw Hill Financial, Morgan Stanley and Cox Enterprises declined to comment.

J.D. "Dave" Power and his wife Julie started the eponymous company in 1968 from their home in Calabasas, California, and later landed Toyota Motor Corp as their first client. It now employs 7000 analysts, statisticians, consultants and other experts in 12 offices globally. McGraw Hill, which has a market capitalization of $25.5 billion, bought the company in 2005 for an undisclosed sum.

Some of J.D. Power's most-read reports rate new and used cars, but it has also branched out to other sectors such as airlines, credit card companies and cable operators. For the past few years, it has faced competition from newer entrants that collect data on customer service.

The Westlake Village, California-based company generated $265 million in revenue in 2013, with the majority of its business coming from the automotive sector, according to a presentation on its website.

It is part of McGraw Hill's commodities and commercial markets segment, which also includes the energy and metals data company Platts. That unit's revenue grew 6 percent to $893 million and had an adjusted operating profit of $306 million last year.

McGraw Hill has been reshuffling its portfolio since it sold its education business to Apollo Global Management LLC in 2013 for $2.4 billion in cash.

It also bought financial data company SNL Financial for $2.23 billion, in a deal that closed in September.

McGraw Hill sold its construction business last year for $320 million in cash to private equity firm Symphony Technology Group.

(Reporting by Liana B. Baker and Jessica Toonkel in New York; Editing by Christian Plumb)

By Liana B. Baker and Jessica Toonkel