Adds details, background, analyst consensus and shares

Feb 4 (Reuters) - In the first outlook presented by new CEO Luke Miels, GSK GSK.L on Wednesday said it expected slower sales growth in 2026 compared with a year earlier, as it expands its pipeline to counter looming patent expiries for its top-selling HIV drugs.

The outlook laid bare the challenge Miels faces as he attempts to deliver commercially from a research ramp-up. The British drugmaker said it still believes it can record sales of more than 40 billion pounds ($55 billion) by 2031.

GSK's shares, which initially fell about 1%, reversed course and were up 1.4% at 0809 GMT.

Investors are closely watching how Miels, who took over from Emma Walmsley at the start of the year, will steer GSK as it navigates U.S. tariffs, policy challenges and as top-selling drugs in its HIV business start to lose their patent protections in 2028.

The current year "will be a key year of execution and operational delivery," Miels said in a statement, adding that the company was well-placed to move forward through its next phase.

SLOWING SALES GROWTH

The firm expects revenue to grow 3% to 5% this year, at constant currency rates, after it rose 7% in 2025 to 32.67 billion pounds, which surpassed expectations of 32.54 billion pounds.

New launches are key for GSK to sustain growth. Last month, GSK made a $2.2 billion offer for RAPT Therapeutics RAPT.O for an experimental food allergy drug. The drugmaker also scored regulatory approvals for five treatments last year.

But uncertainty over GSK's vaccine business, especially in the U.S., is likely to spill over into 2026.

GSK expects 2026 sales from its vaccines business and general medicines unit to decline between a low-single-digit percentage or remain "stable." Its specialty medicines business, though, is expected to report low-double-digit growth.

The company reported core earnings per share of 25.5 pence for the three months ended December 31, after sales rose 8% to 8.62 billion pounds, beating expectations.

($1 = 0.7292 pounds)