By Taos Turner
BUENOS AIRES--Argentine stocks were little changed Friday while the peso was steady against the dollar.
The Merval stock rose 0.13% to 4,181.58 in volume totaling ARS78 million ($13.6 million).
Tenaris SA was the most traded stock, dropping 0.5% to ARS198. It was followed closely in volume by oil producer YPF SA, which rose 0.37% to ARS159.30.
Earlier this week, YPF said it had boosted oil production by 4.7% in July from a year ago and increased gas output by 0.2% from the same month in 2012.
The increased production represents a turnaround since Chief Executive Miguel Galuccio took over the company over a year ago. Mr. Galuccio has been pushing hard to raise production and help the country reverse over a decade of declines in oil and gas output.
YPF's stock is up about 40% over the past year on the New York Stock Exchange, where it closed at $17.77 on Friday.
The TVPA GDP warrant rose 2.04% to ARS72.50 while the TVPY warrant rose 0.51% to ARS69.75.
The Argentine peso weakened to ARS5.702 against the dollar on the regulated MAE foreign-exchange wholesale market, versus ARS5.699 the previous session.
The central bank intervenes in the exchange market daily to buy dollars and build its foreign-currency reserves, while gradually weakening the peso to help exporters.
In the underground market, the peso traded for between ARS9.25 and ARS9.30 to the dollar, according to the newspaper El Cronista, which publishes rates collected from black-market traders.
Some underground traders expect the peso to continue weakening this year. They say it could depreciate sharply after a midterm congressional election in late October.
Some expect the government to further restrict formal access to the dollar then, which could boost demand for greenbacks in the black market.
Strict capital controls that limit the amount of foreign currency Argentines can purchase legally have fueled a parallel illegal market for dollars where people pay a steep premium for the U.S. currency.
Write to Taos Turner at taos.turner@wsj.com