Brent-WTI spread hits two-month high The price difference between the most important oil benchmarks widened to a two-month peak as investors started to shift money from West Texas Intermediate futures into Brent futures owing to changes in key commodities indices. Investors tracking the S&P GSCI and the DJ-UBS commodity indices started an annual rebalancing of contracts on Monday, which will continue until Friday. Although the process usually has a minor impact on prices, this year investors are moving larger than usual amounts of money between oil futures as both indices have boosted the weight of the Brent contract at the expense of its WTI competitor. This month the Dow Jones-UBS commodity index added Brent to its basket, increasing the number of contracts followed by the index to 20. Brent's debut in the index, known as the Dow Jones-AIG on its launch in 1998, reduced the weighting for WTI crude, the US benchmark, from 14.7 per cent last year to 9.7 per cent in 2012. Brent has a 5.3 per cent share in the index. Moreover, S&P GSCI - formerly Goldman Sachs Commodities Index - this month increased the weight of Brent crude to 17.35 per cent from 15.9 per cent in 2011 while the share of WTI will be cropped to 30.25 per cent from 32.59 per cent. Hussein Allidina, head of commodities research at Morgan Stanley in New York, estimated in a note to clients that investors would liquidate WTI contracts worth $7.5bn and almost simultaneously buy $4.5bn in Brent contracts. "WTI should see the largest nominal impact," he said, while warning "the impact of rebalancing on price is, unfortunately, neither definitive nor consistent." Oil analysts said that while the rebalancing was important to the Brent-WTI spread, supply outages in Nigeria, which traditionally affect Brent oil futures far more than WTI futures, were also driving the divergence. Royal Dutch Shell declared force majeure - a legal clause that allows it to walk away from a supply contract - on Nigerian oil exports after a leak in the Bonny Light pipeline. The Brent-WTI spread widened on Monday to $11.14 a barrel, the highest since mid-November. The spread hit a low of less than $6 a barrel two months ago. In London trading ICE February Brent fell 61 cents to $112.45 a barrel while Nymex February WTI dropped 25 cents to $101.31 a barrel.