Zynga's valuation could be on the rise.

The social-gaming company is currently trying to raise about $250 million, the Wall Street Journal is reporting. And if it gathers that much cash, it could see its valuation grow from the $4 billion it was worth in April to "between $7 billion and $9 billion" now, the Journal said, citing unnamed sources.

Zynga's possible decision to take on $250 million in additional financing is somewhat surprising. According to the Journal's sources, the social-gaming company doesn't need the money. However, that isn't stopping it from being courted by several investors who see it as a potential cash cow if it ever goes public.

Since its founding in January 2007, Zynga has witnessed immense growth in its online games, including FarmVille and Mafia Wars, by piggybacking on the success of the world's top social network, Facebook, among other social sites. It now also has a presence on the iPhone and iPad.

According to Zynga's Web site, the company now has over 215 million active users playing its games each month, and more than 50 million people actively playing its titles each day.

Zynga's valuation has consistently been a topic of debate in the gaming industry. In October, a value-tracking service called SharesPost calculated Zynga's value at $5.51 billion. It made headlines because one of the top traditional video game publishers in the industry, Electronic Arts, had a market capitalization of $5.2 billion at the time. Currently, SharesPost values Zynga at $6.17 billion, while EA has a market capitalization of $6.09 billion.

As impressive as Zynga's rising valuation might be, it still pales in comparison with that of Facebook. Last month, it was reported that the social network raised $500 million from Goldman Sachs and Russian investment firm Digital Sky Technologies on a valuation of $50 billion.