* Petrobras shares slide 5% as CEO resists pressure to resign * Mexican peso down for 5th straight day; set for 2% weekly loss * Mexico"s government readying ~$5 bln Pemex lifeline -source By Susan Mathew Feb 19 (Reuters) - Brazil"s Bovespa slid on Friday as oil major Petrobras slumped on concerns about top management, while Mexico"s peso fell for a fifth straight session as the effects of a deep freeze in the neighboring state of Texas spilled over into Mexico, hindering factories. Shares of Petroleo Brasileiro slid around 5%, on course for their worst session since October as its chief executive resisted pressure from Brazil"s President Jair Bolsonaro to resign following tensions over rising fuel prices. While Bolsonaro has expressed sympathy for truckers threatening to strike over higher diesel prices, Castello Branco said their complaints were not the company"s problem and insisted that Petrobras will set prices independently of political pressure. Underperforming regional peers, the Bovespa index slipped 0.9%, putting it on track for a 1% weekly decline. Brazil"s real, meanwhile rose 0.9% against a softer dollar, but as is the case with most emerging market currencies, looked to post declines on the week as rising U.S. Treasury yields squeezed risk assets. Brazil"s Congress will next week analyze a constitutional amendment that aims to revive emergency cash transfers to millions, while examine cuts elsewhere to stop from breaching a spending cap. The country"s stretched fiscal status has weighed on interest in Brazil"s financial markets. Mexico"s peso weakened 0.5% as investors worried about a hit to the country"s manufacturing sector. More companies halted production in Mexico due to power blackouts caused by Texas limiting fuel supply owing to the cold wave there. Electric power and water service slowly resumed at darkened oilfields and refineries in Texas on Friday. The peso has lost about 2% over the last five sessions. Meanwhile, Reuters exclusively reported that Mexico"s government is planning to inject a total of about $5 billion into state oil company Petroleos Mexicanos (Pemex) this year. But market experts were less than enthused. "This is in line with our expectations as well as the long standing government approach of offering ad hoc assistance to Pemex without fixing the core problems," said Citigroup strategists. Concerns about the weight of bailing out the firm on Mexico"s economy have led to downgrades by rating agencies of both the firm and Mexico"s sovereign credit rating. Copper prices rallied and top producer Chile"s peso firmed to six-week highs, while sliding oil prices weighed on crude exporter Colombia"s peso. Key Latin American stock indexes and currencies: Stock indexes Latest Daily % change MSCI Emerging Markets 1429.63 0.32 MSCI LatAm 2394.33 0.56 Brazil Bovespa 118150.93 -0.88 Mexico IPC - - Chile IPSA 4546.74 0.62 Argentina MerVal 51955.35 0.248 Colombia COLCAP 1355.34 0.12 Currencies Latest Daily % change Brazil real 5.3941 0.85 Mexico peso 20.4028 -0.56 Chile peso 704.6 0.82 Colombia peso 3548.51 -0.10 Peru sol 3.6517 -0.02 Argentina peso 89.1400 -0.09 (interbank) (Reporting by Susan Mathew in Bengaluru;)