Pakistan Tourism Development corporation currently offers a Bus Service from lahore to Delhi. For reservations please contact PTDC directly. Following are the details which are taken from the web site of PTDC
Lahore Delhi Bus Service is operated from Lahore terminal 66-D-1, Gulberg III, near market Lahore. For journey to Delhi, there is a PTDC Bus every Monday, Wednesday & Friday and DTC (Delhi Transport Corporation) Bus every Tuesday, Thursday & Saturday. As regards the return trip to Lahore, the PTDC Bus leaves Delhi every Tuesday, Thursday & Saturday whereas the DTC Bus can be had from there on every Monday, Wednesday & Friday.