(Reuters) -U.S. companies borrowed 8.6% more to finance equipment investments in September compared to a year ago, despite continued political and economic uncertainty, the Equipment Leasing and Finance Association said on Thursday.

New loans, leases and lines of credit signed up by companies in September rose to $10.5 billion on a seasonally adjusted basis, marking a 4% increase from the previous month.

September saw the largest single-month increase in new business volumes in nine months, the report added.

"With the Fed resuming its easing cycle, I expect demand to remain strong and financial conditions to improve further," ELFA President and CEO Leigh Lytle said.

The Washington-based trade association represents financial services companies and manufacturers in the $1.3 trillion U.S. equipment finance sector.

The ELFA CapEx Finance Index of leasing and finance activity is based on a 25-member survey, including Bank of America as well as the financing units of Caterpillar, Dell Technologies, Siemens AG, Canon and Volvo AB.

The Equipment Leasing & Finance Foundation, ELFA's non-profit affiliate, sees its October confidence index relatively unchanged at 60.1 from 59.9 in September. A reading above 50 indicates a positive business outlook.

(Reporting by Megavarshini G. Somasundaram in Bengaluru; Editing by Vijay Kishore)