(Reuters) - Italy's Exor SpA (>> EXOR SpA) will consider raising its $6.4 billion (£4.1 billion) offer for reinsurer PartnerRe Ltd (>> Partnerre Ltd) at a board meeting next Tuesday, two sources told Reuters on Friday.

The Italian holding company, controlled by the Agnelli family, made its all-cash offer for PartnerRe in April, disrupting an all-share deal between Axis Capital Holdings Ltd (>> Axis Capital Holdings Limited) and PartnerRe to create one of the world's largest reinsurers with about $11 billion in market capitalisation.

It was unclear how much Exor would raise its bid, the sources said.

On Monday, PartnerRe and Axis reaffirmed a commitment to their negotiated transaction and sweetened the offer under consideration by including a one-time cash dividend of $11.50 per share for PartnerRe shareholders, when the deal closes in the third quarter.

Representatives for Exor did not comment. A PartnerRe representative did not immediately respond to a request for comment. The sources asked not to be named because they were not authorized to speak publicly about the matter.

One source said it was too soon to determine if Exor would consider appealing directly to shareholders by launching a tender offer for PartnerRe shares.

Exor, which controls vehicle maker Fiat Chrysler Automobiles NV , offered $130 per PartnerRe share, a 16 percent premium to the implied value in the original Axis agreement.

Exor boss John Elkann, a scion of Fiat's founding Agnelli family, has said he is keen to branch out into other businesses, including financial service with its steadier and higher returns.

On Monday, PartnerRe said it had rejected Exor's $130 per share proposal, arguing it undervalued the company.

In April, PartnerRe's second biggest shareholder told Reuters that Exor's $130 offer was "much superior" to the deal with Axis.

Exor said on Monday the special dividend offered in the Axis deal would reduce PartnerRe's capital by more than $550 million and significantly weaken the reinsurer's financial strength.

Shareholder and regulatory approvals are pending.

PartnerRe shares were up 2.7 percent to $132.03 in New York trading.

(Reporting by Mike Stone and Greg Roumeliotis in New York; Editing by Ted Botha and Jeffrey Benkoe)

By Mike Stone and Greg Roumeliotis

Stocks treated in this article : Axis Capital Holdings Limited, Partnerre Ltd, EXOR SpA