HOUSTON, March 7 (Reuters) -

Less than a third of companies applying to a U.S. green energy loan program are able to navigate a complex credit review process, with the rest requiring help that slows down approval, a senior administration official told Reuters.

The Department of Energy's Loan Program Office aims to speed development of the clean energy sector with loans to automakers, miners, recyclers and others, many of which would struggle to obtain private financing given their large capital needs.

Lithium Americas Corp and Piedmont Lithium Inc are among the 135 companies that have open applications for a total of $124.1 billion in LPO funding.

For 100 of those applicants, the Energy Department has hired staff to provide business development advice and "intense mentorship," Jigar Shah, head of the Energy Department's Loan Programs Office, told Reuters on the sidelines of the CERAWeek energy conference in Houston.

"They require more hand holding," Shah said. "They're equally innovative. They're amazing. We love all of them equally. But we have a certain bar that Congress has set around the reasonable prospect of repayment. And so everyone has to reach that bar."

Shah declined to provide specifics on applicants, citing U.S. privacy laws.

Given the rapidly evolving technologies in the clean energy space, Shah said the department might shorten loan terms. A project might have to repay a loan in five years as opposed to 20 years, for example.

"We're not supposed to have an opinion that says, 'You know, you cannot get that from us because we think you're going to be superseded by another technology.' If we think that that's a risk, then we just change the terms of the loan," Shah said.

The LPO office would like more applications from electric utilities and oil and gas companies for projects designed to reduce emissions, as well as geothermal companies, Shah said.

"There's a lot of people with existing infrastructure that have published plans for the next 10 years on how they're going to reduce carbon emissions and we can, you know, bring them forward and accelerate those efforts," he said.

Utilities and oil and gas companies can cut emissions with carbon capture and sequestration technologies, by replacing or adding equipment, or by finding and fixing methane leaks.

Shah said his office had recently seen an increase in interest from the offshore wind industry, a sector President Joe Biden's administration hopes to expand as part of its climate strategy but which commercial lenders have been reluctant to engage.

Commercial debt markets are "less interested in the more innovative approaches that (wind companies) are taking. And so we would step in," Shah said.

Li-Cycle Holdings Corp, ioneer Ltd and Syrah Resources Ltd have received loans from Shah's office in the past year.

Ioneer, which is building the Rhyolite Ridge lithium project in Nevada, said less than a month after it received its loan that one of its vendors had violated a minor exploration permit. Shah said given the complexities of many projects his office supports, such minor violations are not deal killers.

"We expect everyone to meet all applicable rules and regulations and whatnot," Shah said. "But at the same time, I'm not going to beat them up for not getting everything exactly right all the time." (Reporting by Ernest Scheyder; Editing by David Gregorio)