India’s Fortis Healthcare (FOHE.BO) has bought more shares in hospital operator Parkway (PARM.SI), setting the stage for a possible battle with Malaysian state investor Khazanah for the Singapore firm.

Fortis bought an additional 350,000 Parkway shares at an average price of $3.1477 on the open market, raising its stake to 25.37% from 25.34% previously, Parkway said in a disclosure statement to the Singapore Exchange on Monday.

The purchase took place last week before Khazanah, which also owns about a quarter of Parkway, made a US$835 million ($1.2 billion) offer to gain majority control of the Singapore firm.

Analysts are speculating Fortis may make a counterbid for Parkway.