NEW YORK, March 13 (Reuters) - Security Capital Assurance Ltd (SCA.N: Quote, Profile, Research) said on Thursday it was no longer writing new business as the bond insurer seeks to preserve capital after posting a $1.2 billion loss for the fourth quarter.

SCA is the latest bond insurer to run into difficulty after guaranteeing repackaged subprime mortgage bonds and other risky debt.

SCA said earlier this month it was reviewing strategic options with a financial adviser, Goldman Sachs, and an advisory boutique, Rothschild Inc.

Security Capital was spun off by Bermuda reinsurer XL Capital Ltd (XL.N: Quote, Profile, Research) in 2006. XL still has a 46 percent stake, and last month reported a $1 billion fourth-quarter loss after writing down its SCA holdings.

SCA posted fourth-quarter losses of $1.2 billion, or $18.67 a share, compared with net income of $35.8 million, or 56 cents a share, in the year-ago period.

(Reporting by Dan Wilchins, editing by Richard Chang)