Oppenheimer estimated first-day sales of Apple's iPhone 4 at 1.5 million units, surpassing previous iPhone launch sales.
The company had sold a million units of the previous version of the iPhone -- the 3GS -- in its debut weekend in 2008.
Oppenheimer, which has an outperform rating on the stock, also raised its fiscal 2010 earnings estimate for Apple to $14.52 from $14.01 a share and fiscal 2011 estimate to $17.96 from $16.71 a share.
Of the 46 analysts covering the stock, 42 have either a strong buy or a buy rating, according to Thomson Reuters Starmine data.
The latest iPhone, which makes possible video calls, can handle multiple tasks simultaneously and has longer battery life than previous versions, went on sale Thursday in stores in the United States, Europe and Japan. It sold a record 600,000 in pre-orders in a single day last week [ID:nN16208936].
The phone's exclusive U.S. carrier AT&T Inc had said last week it had halted pre-orders and that sales would resume as soon as inventory becomes available.
Shares of Apple were down $2 at $267 in morning trade Friday on Nasdaq.
(Reporting by Jennifer Robin Raj in Bangalore; Editing by Saumyadeb Chakrabarty)