The ruckus over bank bailouts in Europe got so noisy last week that echoes reverberated as far away as San Diego.

The European Union is telling the Royal Bank of Scotland to divest itself of certain businesses if it accepts financial aid from the British government.

One of the businesses that has to go: the bank’s 19-month-old commodities trading partnership with Sempra Energy. RBS holds a 51 percent share of the business.

RBS will have to divest itself in four years, the bank said in a lengthy Nov. 3 press release laying out its terms for participating in the British government’s asset protection scheme.

RBS said the commodities joint venture had 2008 income of 765 million pounds, which amounts to $1.25 billion at current exchange rates.

Prior to the joint venture’s kickoff on April 1, 2008, the Connecticut-headquartered RBS Sempra Commodities was known simply as Sempra Commodities. Sempra acquired the metals trading business from Enron in 2002.

Sempra released a statement Nov. 2 saying bank leaders had briefed Sempra executives about the possible divestiture.

The utility said it has the option to reacquire RBS’s share.

“Our agreement with RBS requires that the bank maintain its ownership of the joint venture through April 2012,” said the statement attributed to Sempra Chairman and CEO Donald Felsinger. “We also understand that any forthcoming divestiture order from the European Commission is expected to allow for an orderly transition, comply with our joint venture agreement and be executed in a manner that would maximize the value of the business.

“Our agreement gives Sempra Energy certain rights with respect to any new owner of RBS’s share of the joint venture and also the right to reacquire RBS’s share.

“After discussions with RBS, we are confident that RBS is committed to continuing the capital and credit support for the joint venture going forward.”

RBS Sempra Commodities is the fifth-largest energy trading company in North America, according to the bank.