SHANGHAI/SINGAPORE, July 19 - China is set to keep its lending benchmarks unchanged on Thursday, a Reuters survey showed, after the central bank stood pat on a key policy rate earlier this week even as a rapidly faltering economy raises expectations for more stimulus.

The loan prime rate (LPR) normally charged to banks' best clients is calculated each month after 18 designated commercial banks submit proposed rates to the central bank, the People's Bank of China (PBOC).

In a poll of 26 market watchers, all participants predicted no change to either the one-year LPR or the five-year tenor, partly because authorities are wary of further widening the interest rate differentials with the United States and pressuring an already weak yuan.

The one-year LPR - on which most new and outstanding loans are based - currently stands at 3.55%; while the five-year rate, which serves as the mortgage reference rate, is at 4.20%.

The overwhelming market consensus of steady LPR fixings came after the PBOC rolled over maturing medium-term policy loans and kept the interest rate unchanged this week.

The medium-term lending facility (MLF) rate serves as a guide to the LPR and as a precursor to any changes to the lending benchmarks.

Some traders said the necessity of cutting LPRs was low after a rate reduction in June, as any further easing would widen the yield gap with the United States and risks driving the yuan even lower.

However a sputtering economy has fanned market expectation for more policy measures, with pressure broadening across many sectors and youth unemployment surging to record levels.

"The LPRs were just lowered last month ... let's wait for a possible cut to the banks' reserve requirement ratio (RRR) in the third quarter," said a bond fund trader.

Some analysts said they would pay close attention to the Politburo meeting later this month, when a top decision-making body of the ruling Communist Party meets to discuss the economy.

"We expect policymakers to maintain an easing bias in the July Politburo meeting amid the property sector downturn, weakening exports and soft domestic demand," economists at Goldman Sachs said in a note.

"Having said that, these easing measures will likely be constrained and measured, consistent with the authority's emphasis on the 'high quality growth' model."

(Reporting by Li Hongwei and Winni Zhou in Shanghai, Tom Westbrook in Singapore Editing by Shri Navaratnam)