By Abhijit Neogy and Rajesh Kumar Singh

NEW DELHI (Reuters) - With the economy picking up steam, winding down the fiscal stimulus may be the central theme in the budget scheduled to be presented on Feb. 26.

The government has provided fiscal stimulus worth about 1.86 trillion rupees ($40 billion) in tax concessions and a further $4 billion in new spending since 2008, but this has strained the deficit and borrowing.

Here are some possible scenarios for the budget and its policy and market impact:

PARTIAL WITHDRAWAL OF FISCAL STIMULUS

A partial rollback would help the government bring down the fiscal deficit to it forecast of 5.5 percent of gross domestic product in 2010/11 from a projected 6.8 percent in the current fiscal year.

But the gross market borrowing figure for 2010/11 could still touch 4.61 trillion rupees ($100 billion) because of higher redemptions, according to a Reuters poll of 28 economists.

That would be broadly in line with what the central bank seems to have factored in. It has said it expected gross borrowing to be "slightly higher" than this year's record 4.51 trillion rupees