Royal Bank of Scotland may pursue Goldman Sachs for hundreds of millions of dollars to add to $100 million it got as part of a settlement over the marketing of a subprime mortgage product.

RBS said on Friday it would carefully consider all of its options after Goldman agreed on Thursday to pay it $100 million as part of a $550 million settlement of civil fraud charges over how it marketed the subprime mortgage product.

German bank IKB , the other big loser on the transaction, will be paid $150 million under the settlement, recovering all of its loss.

RBS's options include taking Goldman to court as the U.S. Securities and Exchange Commission said the penalty left the door open for future civil suits.

RBS declined to comment on whether it would sue Goldman for the remaining cash, but some investors have urged it in the past to pursue that route.

Goldman did not admit to any wrongdoing. But it said the marketing materials for the Abacus 2007-ACI transaction contained incomplete information.

It said it was a mistake not to disclose the role of hedge fund Paulson & Co. in picking the portfolio or disclosing that Paulson bet against its performance.

Goldman regrets that the marketing materials did not contain that disclosure, the bank said in a statement.

RBS is 83 percent state owned. Former UK Prime Minister Gordon Brown said in April that Goldman would have to pay back hundreds of millions of dollars if the charges against it were proven.

STATE BAILOUTS

RBS and IKB were the two of the biggest losers of both the controversial product marketed by Goldman and of the wider financial crisis. Each needed billions of euros in state bailouts to survive.

Edinburgh-based RBS paid Goldman $841 million in August 2008 to settle a claim on credit insurance provided by ABN AMRO, the Dutch bank of which RBS had bought parts months earlier.

IKB was brought to the brink of collapse in 2007 in part because of exposure to subprime-related products Goldman sold to IKB's off-balance-sheet investment vehicle Rhineland Funding.

IKB, which required multiple bailouts and is now majority owned by Lone Star , declined to comment before it had a chance to review the SEC settlement.

The payment provided little consolation, if any, given that overall losses were much higher for IKB, said Merck Finck analyst Konrad Becker.

It was too early to say whether the Goldman settlement takes the heat off other banks involved in similar CDOs deals, Becker said, noting the SEC accord resolved only one transaction. (Additional reporting by Edward Taylor; editing by Simon Jessop and Michael Shields)