(Recasts with stocks rising, updates figures)
BUENOS AIRES, Oct 23 (Reuters) - Argentina's peso currency and bonds slipped on Thursday but a power company's shares buyback offer helped the stock market brake a huge three-session slide.
The peso currency fell 0.7 percent to 3.2450/3.2475 per dollar ARS=RASL in formal interbank trade, and was off 0.3 percent to 3.3050/3.3100 per dollar ARSB= in informal trade between foreign exchange houses as measured by Reuters.
Sovereign bonds traded on the local market fell more than 5 percent on average in afternoon trade <AR/BONOS>.
The MerVal .MERV index of leading stocks gained 1.25 percent, bouncing back a bit from a loss of 23 percent over the past three sessions, unnerved by a suprise governmetn plan to nationalize private pensions.
Shares in Pampa Energia (PAM.BA), shot up 8 percent to 0.91 pesos per share after the firm offered to buy back about 4.6 percent of the firm's capital, or 70 million shares at 0.95 pesos each.
Stock in the company, which owns electrical power distribution and transmission firms, closed on Wednesday at 0.84 pesos each.
Argentina's scheme to nationalize private pensions has caused chaos in local markets as investors fear liquidity will dry up because the market's biggest institutional investors could disappear.
Also, investors read the move as a desperate plan by the government to stave off default, although it does resolve short-term debt payment obligations. (Reporting by Walter Bianchi, writing by Fiona Ortiz, Editing by Walker Simon)