CHICAGO, June 13 (Reuters) - The U.S. soybean processing pace likely slowed for a second straight month in May as some crushers idled facilities for seasonal maintenance, analysts said ahead of a monthly National Oilseed Processors Association (NOPA) report due on Thursday.

The monthly crush, however, was still expected to be the largest May crush on record.

NOPA members, which handle about 95% of all soybeans processed in the United States, were estimated to have crushed 175.880 million bushels last month, according to the average of estimates from 10 analysts.

The estimate implies a daily crush rate of 5.674 million bushels, down from 5.774 million bushels a day in April and the slowest daily rate since September, according to NOPA data.

If the estimate is realized, it would be up 1.5% from the 173.232 million bushels processed by NOPA members in April and up 2.8% from the May 2022 crush of 171.077 million bushels, which is the current record for the fifth month of the year.

Estimates for the May 2023 crush ranged from 172.850 million to 179.200 million bushels, with a median of 175.334 million bushels.

The monthly NOPA report is scheduled for release at 11 a.m. CDT (1600 GMT) on Thursday. NOPA issues crush data on the 15th of each month, or the next business day.

Soyoil supplies held by NOPA members as of May 31 were forecast at 1.942 billion pounds, based on estimates gathered from seven analysts.

Soyoil stocks at the end of April totaled 1.957 billion lbs, a 14-month high, while stocks at the end of May 2022 stood at 1.774 billion lbs.

Soyoil stocks estimates ranged from 1.888 billion to 2.050 billion pounds, with a median of 1.925 billion pounds. (Reporting by Karl Plume, Editing by Nick Zieminski)