May 17 (Reuters) - British drugmaker GSK has raised 1.25 billion pounds ($1.52 billion) from a sale of its remaining stake in consumer healthcare company Haleon to institutional investors.

The sale will allow GSK to sharpen its focus on vaccines, cancer and infectious diseases, which are part of CEO Emma Walmsley's plans to boost earnings at the drugmaker.

GSK sold around 385 million shares at 324 pence each, amounting to a 4.2% stake in Haleon. Friday's sale was at a discount of about 2.5% to Haleon's last close of 332.4 pence on Thursday.

Shares in Haleon, created in a merger of GSK and Pfizer's consumer healthcare businesses in 2019, fell as much as 1.7% in morning trade, down 0.7% at 330.1 pence by 0730 GMT. GSK also down 0.7%.

Haleon, in which GSK initially owned nearly 13%, was spun out and listed on the London Stock Exchange in July 2022.

GSK said total proceeds from sales of its Haleon holdings - four in just over a year - stood at 3.9 billion pounds.

The company was the second-largest Haleon shareholder after Pfizer, which currently holds close to a 22.6% after selling a $3.5 billion stake in March. Pfizer remains Haleon's biggest shareholder.

Haleon, which also makes pain-killer Panadol, reported first-quarter revenue slightly below market estimates in early May on lower volumes amid retailer destocking in the U.S. and cooling demand for some of its medicines after a surge last year. ($1 = 0.7898 pounds)

(Reporting by Prerna Bedi in Bengaluru; Editing by Varun H K and Jane Merriman)