TOKYO: Sumitomo Mitsui Banking Corp (SMBC) said it agreed to acquire as much as 40 percent of Indonesian lender BTPN, giving the Japanese bank a foothold in the fast-growing Southeast Asian economy.

SMBC's pursuit of Indonesia's seventh-biggest bank underscores a sustained push abroad by Japanese companies to beat sluggish growth in their home market.

SMBC will first buy 24.26 percent of BTPN for 6,500 rupiah per share, a 14 percent premium to BTPN's last traded price - paying 9.12 trillion rupiah ($937 million) according to Reuters calculations.

It is buying most of it from TPG Capital, which acquired 71.6 percent of Bank Tabungan Pensiunan Nasional Tbk PT (BTPN) in 2008.

For TPG, the partial sale is another example of a profitable exit from a financial services related business in Asia. TPG and its Indonesian affiliate North Star paid about $195 million for the stake in 2008.

SMBC will raise its stake in the Indonesian lender to 40 percent as long as it wins regulatory approval, the Japanese bank said in a statement on Wednesday.

The purchase represents one of the most expensive bank deals in Asia, being struck at a price-to-book ratio of about 4.5, based on Reuters calculations.

SMBC is a unit of Japan's third-largest lender by assets, Sumitomo Mitsui Financial Group Inc (SMFG). It was unclear how TPG plans to exit the rest of its stake in BTPN.

Established in 1958, BTPN operates as a commercial bank with a market value of $3.45 billion, and has more than 19,000 employees and over 10,000 branches.

SMBC's move was first reported by Reuters earlier this month.