E-commerce giant Rakuten Inc. says it has reached a capital alliance agreement with restaurant search business Gurunavi Inc. as it looks to strengthen its foothold in the growing online reservation market.

Rakuten said Monday it will buy Gurunavi shares worth ¥4 billion currently held by Gurunavi Chairman Hisao Taki and acquire a stake of 9.6 percent. The transaction is to be completed Aug. 22.

Data from the Ministry of Economy, Trade and Industry show the market size for online restaurant reservation services in Japan stood at ¥450.2 billion in 2017, up 36.8 percent from the previous year.

In May, e-commerce company Yahoo Japan Corp. announced a business tie-up with restaurant search site operator Retty Inc.

Through the alliance, Rakuten hopes to develop new services and products using customer data collected by Gurunavi. The two companies' customer loyalty programs will also be gradually integrated to enhance services for each other's customers and member stores, Rakuten said.