UPDATE 1-Homebuilder D.R. Horton's profit, revenue beat on higher sales

(Adds details on earnings, estimates)

Jan 31 (Reuters) - D.R. Horton Inc reported first-quarter profit and revenue on Wednesday above Wall Street estimates as the largest U.S. homebuilder sold more homes in a robust housing market.

Orders, an indicator of future revenue for homebuilders, rose 16.4 percent to 10,753 homes in the quarter, a reflection of how job growth is powering demand despite high construction costs keeping prices up.

The company said it expects fiscal 2018 gross margin to be around 20-21 percent, with some fluctuations in the quarters ahead, compared with its prior forecast of around 20 percent.

D.R. Horton said it expects to sell between 50,500 and 52,500 homes in fiscal 2018 and reaffirmed its revenue forecast to be between $15.5 billion and $16.3 billion.

On Tuesday, smaller rival PulteGroup Inc warned of decline in gross margin this year, citing higher land, labor and raw material costs.

But, Pulte joined Lennar Corp in staying upbeat on housing demand despite climbing interest rates and changes in U.S. tax laws related to mortgage debts.

D.R. Horton, which mainly sells single-family homes, said it sold 10,788 homes in the quarter, up from 9,404, a year earlier.

Net income attributable to the company fell to $189.3 million, or 49 cents per share, in the quarter ended Dec. 31, from $206.9 million, or 55 cents per share, a year earlier.

Excluding a one-time charge, the company earned 77 cents per share, well above the average analysts' estimate of 49 cents, according to Thomson Reuters I/B/E/S.

Revenue rose 14.8 percent to $3.33 billion, beating the estimate of $3.26 billion.

Up to Tuesday's close, the Fort Worth, Texas-based company's shares had risen 58 percent this year.

(Reporting by Arunima Banerjee in Bengaluru; Editing by Arun Koyyur)