(Adds BlackRock statement on Argentina, Saudi Arabia)
By Trevor Hunnicutt
NEW YORK, June 20 (Reuters) - BlackRock Inc, the world's largest asset manager, on Tuesday endorsed the decision by U.S. index provider MSCI to add mainland Chinese stocks to one of its key benchmarks.
"We believe our clients will benefit from today's decision to bring Chinese equities into mainstream investment," Ryan Stork, the company's chairman for Asia-Pacific in Hong Kong and one of its most senior executives, said in an emailed statement.
"BlackRock has continued to support all opening of investment in China's onshore capital markets for a number of years."
MSCI said it planned to add 222 Chinese stocks – which will have an initial weighting in the index of just 0.73 percent.
The full inclusion of domestic Chinese stocks in the widely tracked MSCI Emerging Markets Index could eventually pull more than $400 billion of funds from asset managers, pension funds and insurers into mainland China's equity markets over the next decade, according to analysts.
BlackRock manages $5.4 trillion in assets and is a major MSCI client.
MSCI also said it would not yet upgrade Argentina from the frontier market category where it has languished in recent years, and launched a review of its classification of Saudi Arabian markets.
BlackRock portfolio manager Emily Fletcher said that Argentina has significant growth prospects and that "the government has made good progress in dismantling the protectionist structures of the economy."
Fletcher said in a statement that the Saudi Arabia review is "an endorsement of the positive Saudi Arabian stock market reforms" opening that market to more foreign investment. (Reporting by Trevor Hunnicutt; Editing by Dan Grebler and Jonathan Oatis)