Software giant Microsoft Corp. (Nasdaq: MSFT) is reportedly in talks to buy online advertising firm, DoubleClick Inc., according to the Wall Street Journal.

The Journal said Wednesday that DoubleClick is working with investment bank Morgan Stanley as it considers potential suitors. The firm is also mulling a stock market listing, the report stated. The privately held advertising company is seeking at least $2 billion.

The San Francisco based web-firm is owned in large part by private equity firm Hellman & Friedman, which bought DoubleClick for $1.1 billion in 2005.

Shares of Microsoft declined slightly, losing 6 cents, or 0.29 percent to $27.64 on the Nasdaq Stock Market.