* Mexican peso down half a percent * Mexico seeks natural gas supply guarantee after Texas export ban * Brazil"s real dips on full day of trading after long weekend By Susan Mathew Feb 18 (Reuters) - Latin American currencies weakened on Thursday, even as the dollar slid, as an unexpected rise in U.S. weekly jobless claims raised doubts about the pace of recovery in the world"s biggest economy. Brazil"s real fell on its first day of full trading after an extended weekend, extending losses after a slide on Wednesday when it traded half day. Chile"s peso was flat after hitting a six-week peak when it tracked copper prices hitting a nine-year high. Chile is the world"s top producer of the red metal. The U.S. Labor Department"s report showed initial claims for state unemployment benefits were 861,000 last week, compared with 848,000 in the prior week. This put a dent in hopes of a quick global economic recovery from a pandemic-induced slump. Higher oil prices limited losses in crude exporter Colombia"s currency, while Mexico"s peso slipped 0.5%, extending losses to a third straight day. Data on Thursday showed net foreign direct investment in the country fell by 11.7% in 2020. The Mexican government pressed for natural gas supplies after the U.S. state of Texas implemented a ban on exports. Supply from Texas was interrupted by the freeze earlier this week, leaving millions without power and causing an estimated $2.7 billion in losses. "In addition to concerns about an unusually strong winter in some parts of the country and its effect on the economic recovery process, the debate about as to whether and if so to what extent monetary policy will be eased further will be affecting the peso most," said Elisabeth Andreae, FX analyst at Commerzbank. "Following the appointment of a new board member the uncertainty about this matter is particularly high, as it is unclear to what extent Banxico will deviate from its current course." Stocks in the country inched higher with a 7% jump in iron ore prices boosting miner Vale, while oil prices buoyed oil major Petrobras. Shares in Carrefour Brasil jumped after it said it is "optimistic" about margins and as its French parent posted solid full-year results and announced further cost cutting and cash flow targets. Key Latin American stock indexes and currencies: Stock indexes Latest Daily % change MSCI Emerging Markets 1425.83 -1.32 MSCI LatAm 2404.31 -0.48 Brazil Bovespa 120259.89 -0.08 Mexico IPC - - Chile IPSA 4515.68 -0.95 Argentina MerVal 52803.03 0.795 Colombia COLCAP 1364.56 -0.13 Currencies Latest Daily % change Brazil real 5.4287 -0.26 Mexico peso 20.3270 -0.59 Chile peso 713.2 0.00 Colombia peso 3531.85 -0.17 Peru sol 3.6467 0.11 Argentina peso 89.0400 -0.10 (interbank) (Reporting by Susan Mathew in Bengaluru; Editing by Andrea Ricci)