Top Indian private sector lender ICICI Bank (>> ICICI Bank Ltd), which owns nearly 68 percent of the insurer, is selling up to 181.34 million shares in the IPO - the first ever for an Indian insurance company - according to a draft prospectus released on Monday. The proceeds from the sale will go to the bank.

The insurer, expected to be listed later this year, is not selling new shares in the IPO. Britain's Prudential PLC (>> Prudential plc), with nearly 26 percent of ICICI Pru Life, is not selling any of its stake, the document showed.

Primary share sales worth about $6 billion, including a record up to $2.5 billion IPO by Vodafone Group Plc's (>> Vodafone Group plc) Indian unit, are being planned to hit the market in the second half of 2016, according to investment banking sources.

IPO activity in the first half jumped nearly 80 percent to $1.04 billion, Thomson Reuters data showed this month, with the market on track for its best year in six as investors bet on quickening pace of economic growth.

Easing of foreign holding rules in insurance companies earlier this year paved the way for IPOs in that sector, although experts say it will be only the bigger players which will look at a listing.

ICICI Pru Life's rival HDFC Life, a joint venture between India's Housing Development Finance Corp (>> Housing Development Finance Corp Ltd) and Britain's Standard Life Plc (>> Standard Life Plc), had also planned an IPO that sources had said could raise as much as $500 million.

The IPO plans, however, were put on hold as HDFC Life last month began talks to acquire smaller rival Max Life Insurance and its listed parent Max Financial Services (>> Max India Limited), which if successful will make HDFC Life a listed company.

SBI Life, a venture of State Bank of India (>> State Bank of India) and BNP Paribas Cardif SA , by March could announce its intention to go public, its chief executive told Reuters in May, although an actual listing would be two years away.

ICICI Pru Life's IPO is the biggest in rupee terms since state-run Coal India Ltd's market debut in 2010.

($1 = 67.1350 Indian rupees)

(Reporting by Devidutta Tripathy; Editing by Muralikumar Anantharaman and Sherry Jacob-Phillips)

By Devidutta Tripathy