MSCI Inc  the world’s largest index provider, said on Monday it would include the MSCI Saudi Arabia and MSCI Argentina indexes in its closely watched and widely duplicated emerging-markets index, in a move that could draw billions of dollars into the stocks.

MSCI said 30 Saudi Arabian securities would be added, representing an aggregate weight of 1.42% in the MSCI Emerging Markets Index, while eight Argentinian securities would be added at an aggregate weight of 0.26% in the MSCI Emerging Markets Index. All changes will be implemented as of the close of May 28.

MSCI said it would increase the weight of China A shares in the emerging markets index. Twenty-six China A shares - 18 of which are ChiNext stocks - will be added to the MSCI China Index and the inclusion factor for 238 existing constituents will be increased from 0.05 to 0.10.

China A shares will have an aggregate weight of 5.25% and 1.76% in the MSCI China and MSCI Emerging Markets Indexes, respectively.

The weight increase of China A shares in the MSCI Emerging Markets Indexes will be implemented through a three-step process, MSCI said. The FIF-adjusted market capitalization of China A shares will be further increased to 0.15 as part of the August 2019 Quarterly Index Review and then to 0.20, together with the inclusion of Mid Cap China A shares, in the final step as part of the November 2019 Semi-Annual Index Review.

MSCI said 122 securities will be added to and 41 securities will be deleted from the MSCI All Country World Index. In the MSCI World Index, the three largest additions measured by full company market capitalization will be Knorr-Bremse (Germany), Snap A (USA) and Twilio A (USA).

MSCI said late last year it would allow companies that give shareholders unequal voting rights to remain on its current equity indexes, backing down from an earlier proposal that would have reduced exposure to such companies.

Uneven voting structures has been a hot corporate governance topic, especially as a number of newly listed U.S. technology firms, such as Snap Inc SNAP.N and Dropbox Inc DBX.O , have listed shares that retain lopsided decision-making power with company founders and other insiders.

Meanwhile, the three largest additions to the MSCI Emerging Markets Index measured by full company market capitalization will be Saudi Basic Industries Corporation (Saudi Arabia), Saudi Telecom Company (Saudi Arabia) and Al Rajhi Banking and Investment Corporation (Saudi Arabia).

(Reporting by Jennifer Ablan and Trevor Hunnicutt in New York Editing by Matthew Lewis) ((jennifer.ablan@thomsonreuters.com +1 646 223 6297))