(Adds details from statement, background on battle over Hertz)
By Svea Herbst-Bayliss
BOSTON, Aug 21 (Reuters) - Hertz Global Holdings Inc investor Fir Tree Partners on Thursday stepped up its calls for the car rental company to replace its chief executive, saying CEO Mark Frissora "has completely lost credibility."
"It's clearly time to move past denial and swiftly to install great leadership for a great company like Hertz," Fir Tree said in a statement.
Fir Tree has so far been alone in going public with complaints about Hertz' leadership, voicing the increasing frustration with Frissora that other investors privately say they share. Carl Icahn, who announced on Wednesday that he took an 8.5 percent stake and planned to talk to the company's management, has so far been silent.
Earlier this week, Hertz said its 2014 results will miss forecasts because of automaker recalls and accounting problems. But it said in a statement on Wednesday evening that it has a handle on the problems and is working on solving them.
To Fir Tree, which owned 3 percent of Hertz' shares at the end of the second quarter, making it the car rental company's fifth-largest investor, that statement rang hollow.
"We are quite puzzled to read Hertz's assertion that they 'have a good handle on the nature and the scope of the issues' given how many times the company has bungled forecasts in the last year and the shocking lack of financial statements," Fir Tree wrote in its statement on Thursday.
"It made us wonder if we'd read the wrong company's press statement," said the firm, founded by Jeffrey Tannenbaum.
Hertz' stock price dipped 0.5 percent to $30.21 on Thursday after having tumbled 13 percent earlier this week when the forecast was adjusted. It has gained 5 percent since the start of the year.
A spokeswoman for Hertz said the company would not comment beyond the company's statement on Wednesday. (Reporting by Svea Herbst-Bayliss; Additional reporting by Soyoung Kim and Olivia Oran in New York; Editing by James Dalgleish and Dan Grebler)