Pfizer, the world’s largest drug maker, posted a 30 percent decrease in net income for the second quarter on Thursday as it faces strong challenges from generic competitors in the market after losing its patent rights over two of the most profitable drug for the firm.

Pfizer’s net income of $2.42 billion, or 33 cents per share was down from around $3.46 billion, or 47 cents per share a year ago. However, after accounting for the consumer division as a discontinued operation, Pfizer earned $3.66 billion, or 50 cents a share, up from $3.32 billion, or 45 cents a share from the same time last year.

A survey of analysts from Thompson Financial had forecasted earnings of 48 cents per share

Analysts surveyed by Thomson Financial estimated Pfizer would earn 48 cents a share so even without the consumer division the drug maker would beat Wall Street Projection.

The firm reported revenue of $11.74 billion for this quarter a small increase of 3 percent from $11.45 billion.

“We achieved strong operating performance in the face of increased generic competition and revenue losses due to patent expirations, said Hank McKinnell, chairman and chief executive officer for Pfizer.

The first patent to expire was Lipitor, a cholesterol-lowering drug, achieving a 9 percent revenue growth to $3.1 billion. It now faces competition from its original patent holder Merck & Co. and a generic version produced by Zocor.

In addition, was the patent expiry on Zoloft its anti-depressant drug generating $706 million for the second quarter.

More patents would be expired during 2004-2008, where Dr. McKinnell stated, “Pfizer is losing about one third of its Human Health revenue due to patent expirations between 2004 and 2008.”

Despite this negative news, Pfizer still record strong growth for its new products. Celebrex along with seven in line products each are recording double digits growth where Pfizer has place ambitious target for each of them. For Celebrex, the forecast from Pfizer is to reach revenue of at least $2 billion.