Quebec-based Cosmos Capital Inc. said Wednesday it may be willing to raise its hostile takeover offer for Cossette Inc. even higher, but needs access to all of the advertising agency's books.

Cosmos said it would pay $7.87 per share for the shares of the advertising agency the company does not already own, matching an offer by Mill Road Capital LP that values the company at $131.5 million.

3-month stock chart for Cossette Communications on the TSX (CBC)

The company, headed by several former Cossette executives, also said it has asked Cossette for access to all non-public information, which has made available to other bidders.

"Give us access to that confidential information," spokeswoman Sylvia Morin said, adding it could include business plans, financial statements and customer contracts.

"Once we've viewed that we might even consider increasing or putting in a superior offer," Morin said.

The offer by Cosmos expires Dec. 7.

Shareholders reacted positively to the bidding war, sending Cossette shares up 20 cents to $8 in midday trading on the Toronto Stock Exchange.

Cosmos had earlier offered $5.25 per share for Cossette in a deal that valued Cossette at about $87.7 million, but would have cost Cosmos less since it already owns nearly one-fifth of Cossette's stock.

Connecticut-based Mill Road is focused on investments in publicly traded companies under $250 million in size. Its current portfolio includes companies in retail, manufacturing, business services and consumer products industries.

The Quebec ad and communications agency has more than 1,400 employees with offices across Canada and in California, the United Kingdom and China.

Customers include General Mills of Canada, Bell, Coca-Cola Ltd., Hydro-Québec, Sony Ericsson, and Virgin Travel and Virgin Trains in the United Kingdom.