NEW YORK, Nov 28 (Reuters) - Pfizer Inc is disappointed in its performance versus rival GSK in the RSV vaccine market and is working to pick up market share in 2024, Chief Financial Officer David Denton said on Tuesday.

Reuters reported in October that Pfizer's shot was lagging behind the GSK vaccine, which accounted for close to two-thirds of RSV shots given in the U.S. since early September. GSK was helped by being the lone shot offered by CVS.

"If you look at our market share, I don't think we performed as well as we thought we could, or we think we will going forward," Denton told investors at a conference hosted by Evercore ISI analysts.

Denton noted that the company's results had beaten Wall Street expectations in the third quarter because the total RSV vaccine market was bigger than expected. Both shots won U.S. approval for use in adults age 60 and over in May. Pfizer's was also approved for pregnant women to protect their babies.

"There are certain channels where we don't have as much market share. It's been a little bit more exclusive than nonexclusive. I think as we go into 2024, we have eyes on focusing to make sure that we get more than our fair share in the marketplace," Denton said. (Reporting by Michael Erman in New York and Manas Mishra in Bengaluru; Editing by David Gregorio)