LONDON (Reuters) - Britain's largest insurer Prudential (>> Prudential plc) said on Monday it would give an update on its capital position under new EU Solvency II rules on Jan. 19, ahead of other insurers who plan to issue ratios alongside annual earnings statements.

Prudential, Aviva (>> Aviva plc) and the Lloyd's of London insurance market were among 19 insurers to get the green light from the Bank of England on Saturday for so-called internal models of their solvency levels.

It is expected that using "internal models" to calculate these positions will enable insurers to cut capital costs compared with the standard model.

Legal & General (>> Legal & General Group Plc) said on Monday it would give solvency details with its results on March 15, RSA (>> RSA Insurance Group plc) said it would report them on Feb. 25 and Phoenix (>> Phoenix Group Holdings) on March 23.

Aviva (>> Aviva plc) and Standard Life (>> Standard Life Plc) officials said they also planned to issue ratios alongside annual results.

"Even though some of the internal model-related overhang is over, we believe that the market would still like to see more details around headline Solvency II rules, details around assumptions going behind the calculation, and sensitivities around the Solvency II ratio," JPMorgan Cazenove analysts said.

Just Retirement (>> Just Retirement Group PLC) said its merger with Partnership Assurance (>> Partnership Assurance Group PLC) would close as planned during January 2016, following its internal model approval.

Some companies have not applied for internal models yet.

Admiral (>> Admiral Group plc) said on Monday it was expecting to apply in 2017 to use a partial internal model.

UK insurers' share prices rose between 1 and 2 percent, outstripping a 0.6 percent rise in the FTSE 100 index <.FTSE>.

(Reporting by Carolyn Cohn; editing by Sinead Cruise and David Clarke)

By Carolyn Cohn