* Net asset value rises 14 pct to 396 pence a share
* Infrastructure arm to focus on mid-size assets - CEO
* 3i will hold on to Agent Provocateur for now - CEO
* Shares rise, top FTSE performer (Updates to clarify 3i infrastructure bid for Fortum)
By Freya Berry
LONDON, May 14 (Reuters) - Private equity firm 3i reached the end of a three-year restructuring with strongearnings growth at its portfolio companies, helping it post afull-year return on investment of 719 million pounds ($1.1billion).
The British owner of Agent Provocateur and Benelux retailerAction said its net asset value (NAV) rose 14 percent to 396pence a share, despite a negative hit from currency fluctuationsworth 114 million pounds, or 12 pence a share.
The company was the best performer on the FTSE 100 on Thursday, climbing 3.1 percent to 528 pence by 0854 GMT.
Shareholder frustration at weak results and a poor shareprice performance forced a change in leadership at the companyin 2012 and led to the restructuring.
3i has embarked on a selling spree to rebalance its privateequity business, targeting a portfolio of fewer than 40companies. It owned 65 as of end of March this year.
The company realised proceeds of 831 million pounds fromselling assets, while its infrastructure division sawits strongest performance since its 2007 initial public offering(IPO) after selling a stake in Eversholt rail.
"In infrastructure we will focus on more medium-sized coreassets, away from some of the very aggressive pricing we'reseeing from sovereign wealth funds and the like," said ChiefExecutive Simon Borrows in a conference call.
3i's infrastructure division teamed up with Goldman Sachs to bid for the Swedish power grid of Finnish utilityFortum. But the group lost out to Borealis and Swedish pensionfunds in a 6.6 billion-euro deal in March.
The firm proposed a final dividend of 14 pence a share,bringing the total for its 2015 financial year that ended onMarch 31 to 20 pence, the company said in a statement.
3i said it expected to commit between 500 million euros($567 million)and 750 million in four to seven new investments ayear, adding that it would fund this from proprietary capital inthe short to medium term, rather than raising external funds.
Borrows said despite media reports last year, AgentProvocateur was not for sale for now.
"We did take advice from a party to look at the marketrelative to the growth plan of the business. The conclusion wasthat it was performing well and it was better to hold on to fora while," he said.($1 = 0.6352 pounds)($1 = 0.8777 euros) (Editing by David Clarke)
3i Group (III)