Wellington, Dec 23 NZPA - The New Zealand sharemarket posted modest gains today in quiet trading ahead of the Christmas holiday break.

The benchmark NZX-50 index closed up 11.38 points, or 0.343 percent, at 3333.758, having opened slightly ahead. The Australian market was buoyed today by corporate activity and strong commodity prices. Wall Street rose to its highest level since Lehman Brothers collapsed.

Telecom rose 2c to 224, Fletcher Building rose 4c to 783 and Contact Energy rose 8c to 625.

Retailers were mixed after electronic transaction company Paymark said this week that the last weekend before Christmas had not been a good one for retailers. Weaker than expected growth data today also reinforced the view that the economy is struggling to recover. The Warehouse fell 6c to 359 and Michael Hill fell 1c to 87. Hallenstein Glasson was unchanged at 409.

NZ Oil and Gas was unchanged at 83 on a day ACC disclosed it has increased it stake to 6.38 percent from 5.01 percent. OceanaGold fell 8c to 492 as it spelled out plans to increase activity at its Reefton and Macraes open cut mines.

Vector fell 5c to 230 on a day it expressed disappointment with a final determination by the Commerce Commission on input methodologies for electricity and gas distribution businesses. The company is considering if it will pursue appeal options.

PGG Wrightson fell 1c to 48 as it received payments form NZ Farming Systems Uruguay for the previously announced buyout of a management agreement.

Infratil, which released a monthly newsletter updating the performance of its investments, was unchanged at 192. The company this week signalled the early closure of a sale of infrastructure bonds due to strong demand.

Abano Healthcare rose 3c to 484 after saying its Aotea Pathology would provide services to Wellington region district health boards for another three years.

Mercer Group was untraded after reaching agreement with Westpac to extend a funding facility for another year.

US stocks edged higher on Wednesday as gains in financial stocks helped put the S&P 500 on pace for a fifth-straight winning session and lifted the benchmark index to levels not seen since before Lehman Brothers went bankrupt.

The Dow Jones industrial average gained 26.33 points, or 0.23 percent, to 11,559.49. The Standard & Poor's 500 Index gained 4.24 points, or 0.34 percent, to 1255.08. The Nasdaq Composite Index gained 3.87 points, or 0.15 percent, to 2671.48.