RHB Capital Bhd, Malaysia’s sixth-biggest banking group, said it asked the central bank for approval of its proposed purchase of OSK Holdings Bhd’s investment bank.

“An application to Bank Negara Malaysia has been made today for the proposed merger,” RHB and OSK said in separate filings to the stock exchange, without giving details. The lender may pay as much as RM1.9 billion (US$604 million) in shares for OSK Investment Bank Bhd, three people with knowledge of the matter said on Dec. 29.

Buying OSK Investment would allow RHB to overtake CIMB Investment Bank Bhd. as the biggest stockbroker in Malaysia, based on data from the country’s stock exchange. Malaysian banks and brokerages have been merging amid increased competition from foreign lenders such as Bank of China Ltd and Sumitomo Mitsui Banking Corp.

Hong Leong Bank Bhd acquired EON Capital Bhd for US$1.7 billion in May. K&N Kenanga Holdings Bhd, a brokerage part-owned by Deutsche Bank AG, is in talks to buy the investment banking and broking operations of local rival ECM Libra Financial Group Bhd, two people with knowledge of the matter said on Dec. 1.

Both RHB and OSK shares were unchanged at the 12:30 p.m. break in Kuala Lumpur. OSK held at RM1.80 while RHB was at RM7.27.