July 3 (Bloomberg) -- Wendy's International Inc., the U.S. hamburger chain that put itself up for sale in April, is under pressure from Nelson Peltz after the billionaire investor said he is being shut out of the bidding process.

The company didn't respond to a request last week for details about financing available to help fund a purchase, prompting a letter today by Peltz to Wendy's Chairman Jim Pickett. Wendy's shares rose the most in two months.

Peltz, who owns the Arby's restaurant chain through his Triarc Cos., has pressured Wendy's to boost its stock price since he first bought shares in late 2005. Peltz and other investors successfully lobbied Wendy's to spin off its Tim Hortons donut unit and sell its Baja Fresh restaurants in 2006.

``The lack of response from Wendy's and its advisers and the feedback we are hearing from the market clearly indicate that Wendy's would prefer to sell itself to anyone other than Triarc,'' Peltz, the company's largest shareholder, wrote in the letter. The correspondence was included in a regulatory filing.

This week marked Peltz's first opportunity to seek changes at Wendy's since he abandoned a proxy fight with management last year after getting three of his associates on the board. His agreement not to make any demands on Wendy's for a year expired June 30.

Wendy's, the third-largest U.S. hamburger chain, declined to comment on Peltz's letter. ``The special committee of the board will provide comments when they feel it's appropriate,'' Wendy's spokesman Denny Lynch said in an interview.

Trian Hedge Fund

Peltz is the largest shareholder in Wendy's through Trian Fund Management, a hedge fund he started in November 2005 along with Peter May and Ed Garden. Peltz is also chairman of Triarc, which was formed in 1993 when Peltz and May purchased a stake in DWG Corp., the owner of Arby's, and changed its name to Triarc.

Carrie Bloom, a spokeswoman for Peltz, declined to comment beyond the filing. Trian Fund Management owns a 9.8 percent stake in Wendy's.

Shares of Wendy's, which has a stock-market value of $3.34 billion, rose $1, or 2.7 percent, to $38.39 at 1:28 p.m. in New York Stock Exchange composite trading. They have climbed 17 percent since the chain said April 25 that it might consider a sale.

David Palmer, an analyst at UBS Securities LLC, said Peltz's letter may be an attempt to boost the share price, not an indication that he actually wants to buy the company.

``We believe Trian is more likely interested in pushing for a competitive bidding process and a timely sale of the company as a liquidity event to sell its shares,'' Palmer wrote in a research note today. He rates Wendy's shares ``neutral.''

Dave Thomas

Wendy's sales slumped following the death of founder Dave Thomas in January 2002. Sales at Wendy's older stores dropped six quarters in a row before former chief Jack Schuessler resigned in April 2006. He was replaced by Kerrii Anderson.

Wendy's, based in Dublin, Ohio, last month reduced its profit forecast for the year on slowing sales growth and higher commodity costs as customers went to larger rivals including McDonald's Corp.

Triarc and Trian are considering other alternatives for Wendy's, Peltz said today in the filing. They may seek changes in Wendy's management or urge the company to alter the makeup of its board, Peltz said.

The company isn't providing enough information about financing arrangements that may be offered to buyers, Peltz said.

Confidentiality Agreement

Peltz also objects to a new one-year standstill clause in a confidentiality agreement offered to Triarc last month as part of the sale process. It would prohibit him from making a tender offer directly to shareholders.

``While Trian will support the transaction that is best for all Wendy's shareholders, we believe that Triarc is a natural, strategic buyer for the company,'' Peltz said in his letter.

Peltz may be trying to bring Arby's and Wendy's together. Wendy's is known for its hamburgers, while Arby's gets most of its sales from roast-beef sandwiches.

Peltz stepped down as Triarc's chief executive last month. The company plans to move its headquarters to Atlanta from New York and change its name to Arby's.

Sales at Arby's open at least a year have climbed for the past three years, after dropping 2.3 percent in 2003.

Peltz has made investments in other companies, including Heinz Co., to agitate for change. He also has stakes in Kraft Foods Inc. and Tiffany & Co.

Both Wendy's and Arby's rank behind McDonald's and Burger King Holdings Inc. in sales.

To contact the reporter on this story: Josh Fineman in New York at jfineman@bloomberg.net

Last Updated: July 3, 2007 17:16 EDT