According to a regulatory document from Wednesday, an investor consortium led by Trian Fund Management under Nelson Peltz has proposed to acquire Wendy's ($Wendy) for $1.4 billion.

The consortium proposed to privatize the hamburger chain for $7.35 in cash per share, which is a 20% premium over the closing price on Tuesday. In addition to Trian, the consortium members also include investment firms BlueFive Capital and Sixth Street Partners, as well as one of Wendy's largest franchisees, Flynn Group.

Affected by the acquisition offer, Wendy's stock price soared by about 15% in pre-market trading. The Wall Street Journal was the first to report on this proposal from Peltz.

Wendy did not immediately respond to CNBC's request for comment. Trian refused to provide any further comments, except regarding the content of regulatory documents.

At the time of this privatization bid, the hamburger chain company was going through a difficult period of two years. Including the increase on Wednesday, Wendy's stock price has fallen by 65% over this time period. The company has reported declining same-store sales for six consecutive quarters.

The challenges that Wendy faces also make it a cheaper acquisition target for Peltz. Peltz's connection with this brand can be traced back to over 20 years ago, when they initiated an aggressive investment action against that company.

Thrifty consumers have reduced the frequency of dining out, prompting Wendy's and its competitors to offer greater discounts to attract customers. Wendy's has also experienced frequent changes in its CEO, with different leaders proposing various strategies to turn around the struggling chain restaurant business.

In May this year, Potbelly's former CEO, Bob Wright, joined Wendy's and took on the role of the new CEO; the company he previously worked for had already completed its privatization. During the first financial report conference call with analysts in August, he candidly discussed what he considered to be the biggest problems facing the chain brand, including confusion in value positioning, inconsistent store execution, and too many one-time promotional activities.

According to regulatory documents, Trian previously considered acquiring Wendy's in 2022 but later decided to abandon the plan. The company and its related parties currently hold a 16.25% stake in Wendy's.