UPDATE 1-Australia's OneSteel H1 profit up 6.3 pct

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MELBOURNE, Feb 19 (Reuters) - OneSteel Ltd (OST.AX: Quote, Profile, Research), Australia's second-largest steel company, said on Tuesday its half-year profit rose 6.3 percent, missing analysts' forecasts, but maintained its full-year earnings guidance.

The company, which makes long steel products such as bars, pipes and rails, said net operating profit in the six months to Dec. 31 rose to A$104.4 million ($95.8 million) from A$98.2 million a year ago.

That compared with market forecasts of A$132.5 million, according to a Reuters survey of four analysts.

OneSteel maintained its guidance of full-year operating profit before restructuring costs and synergy benefits in the range of A$710-780 million, and said profit comparisons were difficult because of its acquisition of rival Smorgon Steel.

"We quite explicitly at the annual meeting provided our guidance at the earnings level and we also said that our earnings would be heavily skewed towards the second half, and that continues to be the case," Chief Executive Geoff Plummer told a briefing.

OneSteel said the domestic market was mixed, with solid demand in resources and infrastructure and from non-residential construction, while demand remained soft in residential construction, manufacturing and the rural sector.

The company said in November that earnings in its 2008 fiscal year would be skewed to the second half, because of the full contribution of its acquisition of Smorgon, a more favourable pricing environment and higher iron ore exports.

OneSteel bought most of the businesses of Smorgon in a A$1 billion deal last August, in a deal that gave larger rival BlueScope Steel Ltd (BSL.AX: Quote, Profile, Research) the Smorgon distribution division.