By Mrinmay Dey

(Reuters) -Canadian copper miner Teck Resources Ltd has been approached by mining companies including Vale SA, Anglo American Plc and Freeport-McMoRan Inc to explore deals for its base metals business if a planned split of the company happens, sources close to the matter told Reuters on Sunday.

Teck has received expressions of interest from more than six mining companies, which are interested in several other transactions after the split, according to the sources.

These approaches from international miners come as the Vancouver-based miner is fending off unsolicited bids from Glencore Plc.

A spokesperson from Teck said the company does not comment on market rumours or speculation.

Freeport, Vale and Anglo American declined to comment.

Glencore on Tuesday modified its $22.5 billion all-share takeover bid for Teck to include up to $8.2 billion in cash, but Teck's board called it "largely unchanged".

Teck has repeatedly rejected Glencore's offer of merging the companies and subsequently spinning off their combined thermal and steel-making coal businesses, saying it would expose shareholders to thermal coal, oil, LNG and related sectors.

It has instead urged its investors to vote for a restructuring proposal which will see it spin off its highly polluting coal business and focus on production of copper.

Teck investors will decide on the Canadian miner's restructuring plan on April 26.

Influential proxy advisor Institutional Shareholder Services (ISS) on Thursday advised shareholders to reject Teck's restructuring plan on uncertainties and structural issues.

Large investors often follow the recommendations of proxy advisory firms including ISS and its smaller rival Glass Lewis.

The Globe and Mail first reported interest in Teck's base metals business.

(Reporting by Mrinmay Dey and Lavanya Ahire in Bengaluru; Editing by Bill Berkrot and Sandra Maler)