* To pay special dividend of 12.8 pence/share
* 2012 operating profit 900 mln stg vs 853 mln stg consensus
* Regular dividend up 6.5 pct to 14.7 pence
LONDON, March 7 (Reuters) - British insurer Standard Life said its shareholders would get a 302 million pound ($455 million) windfall after strong growth in its home market drove a better-than-expected 65 percent increase in annual operating profit.
Standard Life, Britain's fifth-biggest insurer, will pay a special dividend of 12.8 pence per share, it said on Thursday, on top of a regular payout of 14.7 pence, up 6.5 percent.
Edinburgh-based Standard Life also reported an operating profit for 2012 of 900 million pounds, ahead of the 853 million pounds expected by analysts in a company poll.
The improvement was driven by Standard Life's core British division, where operating profit rose 58 percent.
"Standard Life has delivered a substantial increase in profitability and has a stong capital position supporting increased dividends to our shareholders," Chief Executive David Nish said in a statement.
Standard Life, which was ahead of its main rivals when it began phasing out commission payments to middlemen in 2006, is seen as one of the main beneficiaries of British regulatory changes this year that ban such payments.
The pensions specialist is also expected to gain from new rules which automatically enrol workers into company retirement schemes.
Standard Life shares have risen 60 percent in the past year, beating a 20 percent gain for the European insurance sector as a whole, after the company achieved bigger-than-expected cost cuts in 2012 from investments in new technology.
The stock closed at 375 pence on Wednesday, valuing the company at about 8.6 billion pounds.