(Bloomberg) --

The Johannesburg Stock Exchange will introduce new caps to help investors rebalance weightings after a stock swap between Naspers Ltd. and Prosus NV.

Effective from September, the capping level for the SWIX All Share Index and SWIX Top 40 Index will fall to 6% from 10%, according to a statement from the bourse. The interim measure is designed to align the companies’ combined weighting in key indexes to prevailing levels, JSE said.

The exchange will seek a permanent solution as quickly as possible after a consultation period following publication of a white paper in August.

The deal between South Africa’s Naspers and its spin-off Prosus this week caused havoc, with the JSE forced to delay opening by hours on Wednesday amid the rush of rebalancing trades. 

Read more: Frustrated JSE Traders Idled After Glitch Paralyzes Bourse

“It is important to avoid a temporary structural dislocation in index weightings,” according to the JSE statement.

Naspers is Africa’s largest company by market value. The company’s 31% stake in China’s Tencent has helped to drive up its capitalization in recent years.

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