British drugmaker GlaxoSmithKline PLC on Monday said it plans to raise its stake in its Indian pharmaceutical unit to up to 75% from 50.7% through an open offer. The deal is worth about £629 million ($1.02 billion).

According to a report by Reuters, GSK said it would buy up to 20.6 million shares of GlaxoSmithKline Pharmaceutical Ltd. priced at INR3,100 per share. This is a premium of 26% from its closing market price on Friday.

GSK said that it planned to keep the Indian unit listed even after raising its stake. The transaction will be funded through GSK's existing cash, the report said.

Reuters said GSK is set to spend close to $2 billion in roughly a year to increase its holdings in two listed Indian companies. This underscores the British pharmaceutical corporation's drive to deepen its footprint in emerging markets. GSK is reducing its reliance on traditional prescription drug markets in Western economies where sales are slowing, the report said.

In February, GSK lifted its stake in publicly-listed GlaxoSmithKline Consumer Healthcare Ltd. GSK hiked its holding in its Indian consumer healthcare subsidiary from 43.2% to 72.5% for $901 million, Reuters said.