Judge Pawan Kumar Tiwari said the sentence would be pronounced on July 24.
The case relates to the killing of Pinki Sarkar (20).
Pandher and Koli were held guilty of kidnapping, rape and murder in the case.
Police had discovered 19 skeletons from Pandher's house in Nithari in Noida on December 29, 2006. Pandher and Koli were charge-sheeted in 16 of the 19 cases, while three were closed for want of evidence.
Most of the victims were young girls.
Prior to Pinki Sarkar case the two were convicted and sentenced in six cases, while nine are in various stages of trial, public prosecutor Jaiprakash Sharma said.