The payroll firm said September's jobs gain came to 114,000, down from 162,000 announced in early October.
From September to October, the firm said, businesses with under 50 employees added 50,000 jobs, while those with 50 to 500 employees added 27,000 jobs.
Larger companies added 81,000 jobs in the month, the firm said.
The trend is a clear departure from most of the recovery, which has been dominated by job growth among small companies with the largest firms lagging far behind.
ADP said service oriented firms added 144,000 jobs in October, matching the sector's gain from September. Goods producing firms, meanwhile, added 14,000 jobs in the month.
Construction added 23,000 jobs in the month -- a sector that is likely to remain strong in November, given estimates of damage caused by Hurricane Sandy hover around $20 billion.
Manufacturing lost 8,000 jobs, while trade, transportation and utilities gained 24,000.
The finance sector added 9,000 jobs in the month, while professional services added 35,000, ADP said.