Abbott Laboratories increased its full-year adjusted earnings forecast on Wednesday as a rebound in COVID-19 test sales and strength in its mainstay businesses helped the medical device maker beat quarterly profit estimates.

The medical device maker's shares were up 2.8% at $122.80 in premarket trading.

The number of COVID-19 tests has reduced from the peak of the pandemic as more people get vaccinated in the United States, but their demand has increased in recent months as employers and schools implement screening programs.

The U.S. government has also announced policies aimed at pushing large employers to have their workers inoculated or tested weekly and has so far invested around $3 billion to procure rapid COVID-19 tests from Abbott and other manufacturers. 

Rival Quest Diagnostics Inc raised its full-year profit outlook in September saying it expects an uptick in COVID-19 testing demand. 

Third-quarter sales at Abbott's diagnostics business grew 48.2% to $3.91 billion, with coronavirus test-related sales at $1.9 billion, up from $1.3 billion in the second quarter.

The company said the majority of demand was for its rapid COVID-19 tests.

Abbott raised its outlook for 2021 adjusted earnings from continuing operations to between $5.00 and $5.10 per share, compared with its previous forecast of $4.30 to $4.50 per share.

On an adjusted basis, the company earned $1.40 per share, beating estimates of 95 cents per share, according to Refinitiv IBES data.

Revenue for the third quarter was $10.93 billion, compared with estimates of $9.56 billion.

(Reporting by Mrinalika Roy in Bengaluru; Editing by Sriraj Kalluvila and Shounak Dasgupta) ((mrinalika.roy@thomsonreuters.com))