(Adds details on case, other settlements, byline)
By Jonathan Stempel
June 19 (Reuters) - Royal Bank of Scotland Group Plc agreed on Thursday to pay $99.5 million to resolve a U.S.regulator's claims against the bank over Freddie Mac's purchase between 2005 and 2007 of mortgage-backed securitiesthat later went sour.
The Federal Housing Finance Agency said the accord relatedto litigation also naming Ally Financial Inc, which previouslysettled, as a defendant.
The FHFA said it has now reached 15 settlements, totalingabout $16.1 billion, stemming from lawsuits it filed in 2011 torecoup losses on roughly $200 billion of mortgage-backedsecurities purchased by Freddie Mac and Fannie Mae.
The FHFA oversees both government-controlled mortgagecompanies as conservator.
It still has a case against RBS in federal court inConnecticut, which it has said concerned about $30.4 billion ofsecurities, and cases in federal court in Manhattan againstGoldman Sachs Group Inc, HSBC Holdings Plc andNomura Holdings Inc.
In a statement, RBS said the settled case concerned morethan $2 billion of securities, It said it previously set asideenough money to cover the settlement amount. RBS said that othermortgage securities cases may be resolved differently.
Bank of America Corp and its Countrywide and MerrillLynch units have reached three of the 15 FHFA settlements. Thosethree settlements total $5.83 billion, a larger amount than atany other bank.
The FHFA became the conservator for Freddie Mac and FannieMae after federal regulators seized those companies in September2008.
The case is FHFA v. Ally Financial Inc et al, U.S. DistrictCourt, Southern District of New York, No. 11-07010. (Reporting by Jonathan Stempel in New York; Editing byMarguerita Choy and Leslie Adler)