BLUE CHIP stocks posted modest gains yesterday in mostly technical trading linked to the expiration of contracts from last Friday's triple witching hour.

The Dow Jones picked up 12.56 points (0.22 per cent) to close at 5,717.79. Some 336 million shares changed hands on the New York Stock Exchange, with winners ahead of losers 1,332 to 1,010 and 813 issues unchanged.

On the bond market, the average rate on the benchmark 30 year Treasury bond eased to 7.09 per cent from 7.10 per cent late on Friday, in the absence of fresh economic data.

Investors remained cautious ahead of next week's meeting of the Federal Reserve Open Market Committee, which determines monetary policy.

Data this week will include consumer confidence figures, durable goods orders and a final report on US economic growth.

June unemployment data will be released next week.