JOHANNESBURG (Reuters) - South Africa's rand retreated on Tuesday as a suspected bomb attack in the United Kingdom spurred investor flight to safe-haven currencies amid broad risk aversion globally. At 0640 GMT, the rand weakened 0.2 percent to 13.2775 per dollar compared to a close of 13.2500 in New York on Monday. British police said 22 people including some children were killed in a suicide attack carried out by one man after a Ariana Grande concert in Manchester on Monday. On Monday S&P Global Ratings revised Brazil's outlook to "CreditWatch negative," which means it can downgrade the country over the next three months, sparking jitters toward other emerging markets. Rand struggling to break out of significant technical ranges ahead of consumer inflation, interest rates releases later in the week. Traders see technical stop near 13.40. Stocks edge lower, with the Top-40 index down 0.08 percent. In fixed income, the yield for the benchmark government bond due in 2026 up 2 basis points to 8.645 percent. (Reporting by Mfuneko Toyana; Editing by Ed Stoddard)