Canada's largest stock exchange operator TMX Group said on Saturday it had received a takeover offer from a group of Canadian banks and pension funds that rivals a $3 billion London Stock Exchange bid.

TMX did not say how much the financial institutions calling themselves the Maple Group Acquisition Corporation bid, stating only it was above the current market price for TMX shares.

The Maple proposal, which is not binding and was prepared for discussion purposes, provides for a combination of cash and equity consideration stated to be at a premium to the current market price of TMX Group shares, TMX said in a statement.

The exchange operator said the Maple Group was made up of a number of Canadian financial institutions, including pension funds and banks.

The announcement follows speculation in the local media that three of Canada's biggest banks and a number of its major pension fund managers were considering ways to block the LSE's bid, including a rival offer.

The media reports said there has been speculation that a counterbid for TMX could be launched by Canadian banks, possibly through Alpha Group, an alternative trading system that was founded by Canada's biggest banks and the Canadian Pension Plan Investment Board.

But two of Alpha's shareholders, Bank of Montreal and Royal Bank of Canada, are advisers in the LSE-TMX deal and support it.

TMX Group will make no other public comment on the Maple proposal until the Board of Directors has completed its analysis, the company said.

The LSE launched its friendly bid for the TMX, which has one of the largest concentrations of mining shares in the world, on February 9. The proposed deal has met with opposition from some Canadian banks, politicians and companies.

(Reporting by Pav Jordan; Editing by Paul Simao and Laura MacInnis)