By Nichola Groom and Matt Daily

DALLAS (Reuters) - First Solar Inc does not expect any delay in the completion of its massive Topaz solar power project in California despite not having clinched a U.S. Department of Energy loan guarantee to finance it.

The U.S. solar company is in advanced talks with several potential buyers for the project, a senior executive said on Wednesday.

"We have been pleasantly surprised that it was not a single party that we were able to sit at the table with, which for that size project was fantastic," Jim Lamon, senior vice president of engineering, procurement and construction, said in an interview.

First Solar, the world's most valuable solar company, secured DOE loan guarantees for three major projects this year. They were then sold to NextEra Energy Inc, NRG Energy Inc and Exelon Corp.

The 550-megawatt Topaz project in Central California did not meet the Energy Department's strict September 30 deadline.

Topaz is contracted to begin shipping power to utility Pacific Gas & Electric by the end of 2012, with full completion of the project slated for 2014.

First Solar is the global leader in low-cost solar panels thanks to its cadmium telluride technology, which does not use the pricey silicon contained in traditional panels.

Recently, however, makers of silicon-based panels have been closing the gap with First Solar as prices on their products slumped due to a global oversupply.

First Solar is confident, however, in its ability to maintain its position as the low-cost leader, Lamon said.

"We've stepped up our game," he said, adding that the company's costs for components other than solar modules are also lower than competitors. In addition, First Solar's construction team benefits from working with the same product every time, constantly becoming more efficient.

"We are hell-bent on keeping that wide margin," Lamon said.

(Reporting by Nichola Groom and Matt Daily, editing by Matthew Lewis)