Finance Minister P Chidambaram has said setting up of large taxpayer units (LTUs), aimed at providing single window for big assesses, will take at least six months."It will take minimum six months to set up large taxpayer units since the whole design for such units is yet to be prepared," Finance Minister P Chidambaram told PTI.Setting up of LTUs is part of this year's budget."As a measure of facilitation, I propose to follow international practice and establish LTUs. To begin with, these units will be set up in major cities. I would like to invite large taxpayers, whether of corporate tax or income tax or excise duties or service tax, to participate in the programme and avail of the single window service," the Finance Minister had said in his budget speech.To begin with, LTUs will be set up in Delhi, Mumbai, Kolkata, Chennai and Bangalore.Already, another of the budget proposal to set up Help Centres for facilitating small tax payers file tax returns have been operationalised.About 130 such centres have started operations from July one.While around 80 such centres have come up for direct taxes, 50 started operations for indirect taxes.