HOUSTON (Reuters) — Bermuda-based Nabors Industries Ltd. , the world’s biggest land-based oil and gas driller, said yesterday its first-quarter earnings would fall well short of Wall Street estimates after weather disrupted its North American rig activity.Warmer temperatures in Canada forced producers to halt operations there earlier than usual, while ice storms in Texas, Oklahoma and California reduced well-servicing rig hours, Nabors said.

The statement comes less than two weeks after No. 2 oilfield services company Halliburton Co. warned its quarterly profit would lag analysts’ expectations because of decreased drilling operations.

In January, Nabors told investors its fourth-quarter profit would miss analysts’ estimates due to weakness in North American drilling markets.

“We believe that we may continue to see a great number of idle rigs as companies lay down rigs in order to keep margins steady,” Mark Urness, an analyst at Calyon Securities, wrote in a note to clients.

Urness lowered his price target on Nabors shares to $30 from $32.

The Houston-based company’s shares fell 2 percent to $29.84 in morning trade on the New York Stock Exchange, underperforming the Philadelphia Oil Services Index, which was up slightly.

Higher costs from start-up and moving delays in international and offshore operations also weighed on results, Nabors said.

It said it expects earnings of 80 cents to 85 cents a share for the first quarter. Analysts on average had called for $1 before exceptional items, according to Reuters Estimates.

About 30 percent of the variance from the analysts’ consensus was due to an internal review to determine whether the company’s options-granting practice was proper, Nabors said.

The probe found a number of stock options were misdated, but the company said there was no evidence of intentional wrongdoing. The matter is also under review by the US Securities and Exchange Commission.

Nabors said it currently has about 60 idle rigs in its continental United States drilling operation, an increase of 36 from the beginning of the quarter.

In Canada, lower activity and an early spring thaw are likely to result in an average of only 57 rigs operating in the seasonally peak first quarter, compared with 73 in the first quarter of 2006, the company said.

Rig margins, however, remain resilient, with renewal contracts generally steady to current levels, the company said.

Nabors also said it faces higher property taxes because of a change in the Texas laws that count the rigs in the county of the owner’s domicile rather than the location of the rig.