By Maggie Fick and Jacob Gronholt-Pedersen

COPENHAGEN (Reuters) - Novo Nordisk reported on Wednesday better-than-expected quarterly sales of its popular Wegovy weight-loss drug, reassuring investors worried the drugmaker was losing its lead in the fast-growing obesity drug market to U.S. rival Eli Lilly.

Shares in Novo Nordisk, a first mover in an obesity drug market that some analysts forecast could be worth about $150 billion by the early 2030s, were up 7.6% by 0855 GMT, among the biggest gainers in Europe.

Sales of Wegovy totalled 17.3 billion Danish crowns ($2.5 billion) in the third quarter, ahead of the 15.9 billion expected by analysts in a company-compiled consensus and up 48% from the previous quarter.

But total group sales, which rose 21% to 71.3 billion crowns, came below the 72.3 billion crowns expected by analysts due to weaker-than-expected diabetes drug Ozempic sales.

The company said U.S. sales growth was hurt by the phasing of rebates - volume-based discounts negotiated by pharma companies with U.S. pharmacy benefit managers - in 2023.

"Wegovy continues to gain momentum and clearly exceeds expectations in the quarter," compensating for weaker diabetes sales, Sydbank analyst Soren Lontoft Hansen said.

Analysts said the Wegovy sales beat was a relief, though pricing pressure in the U.S. was slightly worse than they expected.

Investors were nervous ahead of the results as Novo Nordisk goes head to head with rival Eli Lilly which launched its drug Zepbound in December last year. Last week, Lilly posted results for its weight-loss sales that fell short of expectations.

Wegovy and Zepbound are part of a class of drugs that mimic an intestinal hormone called GLP-1, either on their own or in combination with compounds that target a second hormone to create a sense of fullness and reduce appetite.

Novo's leading position in obesity drugs, coupled with ferocious demand which has outpaced supplies, helped make it Europe's biggest company by market capitalisation last year. It is now worth $489 billion, but has lost 28% of its value since peaking in June.

OUTLOOK

Novo CEO Lars Fruergaard Jorgensen told a media briefing after the results that the company continued to see "very significant demand" for Wegovy in the United States and was working hard to increase its manufacturing capacity.

He did not say whether the company had lifted the curbs it had placed on the lowest doses of Wegovy that have been in force since May 2023 to cope with overwhelming demand.

Wegovy has now been launched in more than 15 countries, the company said on Wednesday, but declined to name the additional nations since August when it said it was in 12 countries.