The Australian share market has come off highs reached yesterday, as regulatory hurdles put a dampener on the proposed merger between the ASX and Singapore Exchange. The All Ordinaries Index is down 16.6pts or 0.3pct to 4764 despite a positive lead from offshore markets and firmer commodity prices.

Shares in ASX Limited (ASX) are down 4.8pct to $39.75 in early trade, after rising 19.5pct yesterday on the merger announcement. The $8.4 billion deal is still subject to approval from the Federal Government, Securities and Investments Commission and the Singapore Monetary Authority.

Elsewhere financial stocks are also dragging. The Commonwealth Bank (CBA) has today held its Annual General Meeting, with CEO Ralph Norris indicating funding costs for banks remain high. CBA shares are down 0.6pct to $50.66 while the NAB (NAB) is off 0.3pct to $24.93. Shares in Macquarie Group (MQG), which rose more than 4pct yesterday, are down 1.3pct to $34.52.

The big miners have given up early gains, with BHP Billiton (BHP) lower at $41.62 and Rio Tinto (RIO) down 0.2pct to $83.94. Shares in Fortescue Metals Group (FMG) have risen 1.1pct to $6.62 while Newcrest Mining (NCM) is lower by 1pct to $41.

Telstra (TLS) shares are up 1.1pct to $2.67.

The Australian dollar is worth US99.12c, £0.6302 and €71.07c.