(Reuters) – MSCI Inc said on Monday it would include the MSCI Saudi Arabia and MSCI Argentina indexes to its closely watched and widely duplicated emerging-markets index.

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.

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.