Online coupon site Groupon and Internet radio company Pandora are moving ahead with plans for initial public offerings, sources familiar with the matter told Reuters.

Chicago-based Groupon is meeting with bankers to explore prospects for a "meaningfully-sized" IPO after a recent bid from Google Inc. — reported at $6 billion — fell apart, one source said.

The company's IPO could be for $1 billion to $1.5 billion, CNBC reported.

If the IPO goes ahead, it would rank among the largest tech IPOs in the United States of the past decade, according to Thomson Reuters data.

It also may be an early sign that tech companies are eager to take advantage of higher valuations triggered by the $450 million investment in Facebook by Goldman Sachs and Russian firm Digital Sky Technologies that values the online social networking company at $50 billion.

"Tech was always expected to be a big part of new issuance this year but it does seem as though the Goldman-Facebook announcement and Facebook's valuation in the secondary markets has really accelerated plans for some of the leading tech companies," said a source familiar with the matter.

Pandora met with bankers Tuesday about a possible $100 million IPO and could pick banks to lead the offering as soon as Friday, that source said.

The source was not authorized to speak publicly and declined to be named. Groupon was not immediately available for comment. Pandora declined to comment.

LinkedIn plans to go public this year, sources have said. Microblogging site Twitter and Zynga, which develops social online games, also are seen as potential IPO candidates.

Groupon has aggressively been raising capital. In December it sold a $500 million equity stake, and Monday, it announced it had completed a $950 million round of financing.