S&P is the only of the three major credit agencies with a 'negative' outlook on India.
The rupee which has been relatively stable over the last couple of months after having seen as much as 20 percent fall to a record low in late August has been boosted mainly by robust foreign fund inflows into the stock market.
The partially convertible rupee closed at 61.2350/2450 per dollar compared with 61.31/32 on Tuesday.
The future action on rate change will depend on data said the RBI Chief.
The RBI's macroeconomic report released after the close of markets said upside risks to food inflation remain and that it expects the retail and wholesale price inflation to remain above comfort levels.
The central bank is widely expected to increase the repo rate by 25 basis points on Tuesday to 7.75 per cent to fight inflation even as it continues to unwind its rupee defense steps, a Reuters poll showed.
India plans to launch trading of government bond futures within the next two months as part of efforts to deepen its financial markets, according to several sources involved in the discussions with the central bank.
The plan being negotiated by US Senate leaders would end a partial government shutdown and raise the debt ceiling by enough to cover the nation's borrowing needs at least through mid-February 2014, a source familiar with the negotiations told Reuters.
The investment bank adds that company's September-quarter earnings came in line with consensus estimates.
The rupee resumed lower at 61.15 per dollar as against the last weekend's level of 61.07 at the Interbank Foreign Exchange market and hovered in the range of 61.15 and 61.28 before quoting at 61.24 per dollar at 1030 hours.
Sentiments turned buoyant after RBI on Monday cut the marginal standing facility rate, at which it lends emergency funds to banks, by 0.5 per cent to 9 per cent with an aim to improve liquidity and boost economic activities.
Traders say the rupee and other global currencies will likely track the continued uncertainty in the US budget stalemate and government shutdown.
The RBI's comments, announced after trading hours on Wednesday, comes as yields had risen by 60 basis points after a surprise hike in the repo rate on Friday and on worries about the fiscal second borrowing programme of the government.
The partially convertible rupee closed at 63.37/38 per dollar compared with 62.83/84 on Monday. The unit dropped 0.85 per cent on the day, its biggest single-day fall in two weeks.
In the global markets, the US dollar traded lower in early trade after former US Treasury Secretary Larry Summers withdrew himself from the race to be the next Federal Reserve chairman.
The bank says the rupee can reach 57-58 levels though the RBI may try to stem the volatility by starting to build reserves at 60.
After hitting a record low of 68.85 to the dollar last week, a Reuters poll suggests the rupee will stabilise at 66 to the dollar by the end of September, while technical charts also point to a period of relative calm.
The RBI has bought Rs 124.62 billion worth of bonds since its announcement on Aug. 20 that it would occasionally buy bonds to relieve some of the cash tightness in the banking system.
The central bank was seen selling dollars consistently when the rupee would approach the record low of 68.86 hit on August 28.
The partially convertible rupee was trading at 65.87/88 per dollar.