We asked the question the other day if Google gross revenue would decline for the first quarter, since going public.

Today, Google released earnings after the market closedand the answer was yes.

Google for the first time since going public in 2004, saw its gross revenue decline 3% from the previous quarter but it was still up 6% compared to the same quarter last year.

Google reported revenues of $5.51 billion for the quarter ended March 31, 2009, an increase of 6% compared to the first quarter of 2008 but a decrease of 3% compared to the fourth quarter of 2008.

Net income for the three months ended March 31 totaled $1.42 billion, or $4.49 per share, compared with $1.31 billion, or $4.12 per share, a year ago.

Google-owned sites generated revenues of $3.70 billion, or 67% of total revenues, in the first quarter of 2009. This represents a 9% increase over first quarter 2008 revenues of $3.40 billion and a 3% decrease from fourth quarter 2008 revenues of $3.81 billion.

Google’s partner sites generated revenues, through AdSense programs, of $1.64 billion, or 30% of total revenues, in the first quarter of 2009. This represents a 3% decrease from first quarter 2008 network revenues of $1.69 billion and a 3% decrease from fourth quarter 2008 network revenues of $1.69 billion.

Aggregate paid clicks, which include clicks related to ads served on Google sites and the sites of AdSense partners, increased approximately 17% over the first quarter of 2008 and increased approximately 3% over the fourth quarter of 2008.

“Despite the tough economic climate, we had a good quarter,” chief executive Eric Schmidt said in a conference call. “But no company is recession-proof, and Google is definitely feeling the impact.”

Consumers are still searching on Google, but they’re buying less, Schmidt said. “The shift to online gives us an advantage, so we’re well-placed for the recovery when it occurs,” he said.

Google share were basically flat, in after market trading, after the earnings were released.