Global miner Rio Tinto is to review the terms of its $19.5 billion deal with Chinese aluminium maker Chinalco following regulatory delays, London's Daily Telegraph newspaper reported.

Australia extended its review of Chinalco's investment in Rio on Monday as Rio shareholders voiced growing concern over the deal.

The Daily Telegraph in its Tuesday edition quoted unnamed sources as saying Rio would use the extra 90 days to conduct a review of both the terms and whether it should raise the approval threshold from 50 percent to 75 percent when the deal is put to a shareholder vote.

Some Rio shareholders have said they would prefer to vote on a special resolution on the Chinalco deal as that would require 75 percent approval. An ordinary resolution requires 50 percent approval.

A spokesman for Rio declined to comment on the Telegraph story but the company has said the Chinalco deal would give it access to cheaper financing.

A spokesman said earlier in the day that shareholders were entitled to their view and that the group continued to listen to them.

Under the deal announced last month, state-owned Chinalco would pay $12.3 billion for stakes in debt-saddled Rio's key iron ore, copper and aluminium assets and $7.3 billion for convertible notes that could double its equity stake in Rio to 18 percent. (Reporting by Kate Holton; Editing by Phil Berlowitz)

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