Shares rose about 5% as the company, best known for its national chain of retail drugstores, also reiterated its recently issued 2021 adjusted earnings per share forecast range of $7.56 to $7.68.

CVS bought Aetna in 2018 to help tackle soaring healthcare spending through lower-cost medical services in pharmacies, and Guertin played a key part in the $69 billion deal.

"Guertin is no stranger to CVS. He was lined up to become CFO of the company following the Aetna deal in 2018," Baird analyst Eric Coldwell said in a client note.

Guertin, who was with Aetna for eight years, left CVS in 2019 for "personal and family reasons", according to the company.

He will now take charge on May 28 and succeed Eva Boratto, who is leaving the company after 11 years.

This is the second top-level appointment of a former Aetna executive at CVS. The health services company had in February named former Aetna President Karen Lynch as its chief executive officer to succeed long-time boss Larry Merlo.

"His (Guertin's) appointment marks further migration of CVS's senior leadership toward the MCO (managed care organization) side," RBC Capital Markets analyst Anton Hie said.

CVS is betting on its Aetna health insurance and pharmacy benefits management units to drive growth this year as its retail segment recovers from a sales hit due to the curbs imposed last year to control the pandemic.

(Reporting by Manojna Maddipatla and Amruta Khandekar in Bengaluru; Editing by Vinay Dwivedi and Sriraj Kalluvila)

By Manojna Maddipatla and Amruta Khandekar