* To be the 3rd-biggest IPO in the world so far this year

* IPO could raise around $3.5 bln based on Shanghai shares

* Hong Kong IPO seen at 20 pct discount to Shanghai price

* Carlyle expected to sell part of its stake after IPO (Adds price estimates, details, adds HONG KONG dateline)

By George Chen and Lu Jianxin

HONG KONG/SHANGHAI, July 17 (Reuters) - China Pacific Insurance (601601.SS: Quote, Profile, Research), part owned by the Carlyle Group, confirmed on Friday it would relaunch a Hong Kong initial public offering which would be the world's third-largest IPO so far this year.

The plan to relaunch the IPO, confirming a Reuters report on Wednesday, follows China Pacific's failure to float its shares in Hong Kong last year when capital markets plunged amid the global financial crisis. The company is already listed in Shanghai.

In a statement released on Friday, the country's third-largest life insurer said it would offer up to 1 billion shares in Hong Kong at no less than the average price of its Shanghai-listed A shares in the previous 20 trading days.

Based on those figures, China Pacific could raise around 24 billion yuan, ($3.5 billion) if successful. It tried to raise more than $4 billion last year in Hong Kong.