Seven Group, controlled by billionaire Kerry Stokes and his family, has lifted its stake in the building products maker to 78.8% from 71.6% since first making an attempt in February to acquire full control of the company.

The deal on offer now comprises 0.1116 Seven Group shares and A$1.70 per share in cash and dividends for the stake it does not own in Boral.

That is higher than the earlier offer with a cash component of A$1.50 a share that was to increase if the bid met certain requirements. Boral's independent directors told investors to reject the original offer and said it undervalued the company, citing an independent expert's report.

Under the revised offer, Boral shareholders will receive the equivalent of A$6.16 to A$6.39 per Boral share, including dividends from both companies, and $A0.13 per share in franking credits.

Boral shares were trading 1.8% higher at A$6.14 as of 0200 GMT on Friday, while Seven Group shares were 0.05% higher at A$40.05.

Boral said independent expert Grant Samuel had formed the view that Seven Group's revised offer was now reasonable.

The terms of the new deal give Boral an option to buy back a maximum A$350 million of shares on market, the company said.

($1 = 1.5293 Australian dollars)

(Reporting by Himanshi Akhand in Bengaluru and Scott Murdoch in Sydney; Editing by Subhranshu Sahu and Jamie Freed)