SAN FRANCISCO -- With shares of Yahoo! ( YHOO) continuing a staggering fall, one investor is now urging Microsoft ( MSFT) to use it as an entry point for another acquisition bid. Mithras Capital, which owns 1.9 million shares of Yahoo! - or about .14% of the company -- proposes in a letter to Microsoft and Yahoo! that the Redmond-based software company purchase the Internet giant for $22 a share. That's far lower than the $33 that Microsoft had offered earlier this year but still an 81% premium over Yahoo!'s current stock price. Yahoo! has fallen below its five-year low in the last couple of days as the market continues to take a beating amid unrelenting investor fears, along with analysts' concerns that the company will be hurt by weakening display advertising spending. On Friday, the stock was down 3.9% to $12.16 in intra-day trading . Mark Nelson, a partner for Mithras Capital, maintains that $22 a share is a fair price for Yahoo! when valuing the different parts of the company separately. "Six or nine months ago when the multiples were higher, $29 or $30 made sense," he said in a phone interview. "A reduced price does seem logical. It's a premium most Yahoo! shareholders would welcome and it's still equal to the price that Yahoo! was trading at Microsoft's original bid." Yahoo! was trading at $19.18 on Jan. 31 when Microsoft offered an unsolicited bid of $31 a share for the company. Microsoft later bumped the price to $33 but the two sides could not reach an agreement.