Marriott Corp. reported yesterday that it reached the billion-dollar sales mark in fiscal 1977, with a 15 per cent increase in revenues over 1976 and a 17 per cent rise in earnings.

The Washington-based company said sales totaled $1.03 billion in the year ended July 29, up from $890.4 million a year earlier, with profits of $36.09 million (99 cents a share) compared to $30.8 million (88 cents).

[TEXT OMITTED FROM SOURCE] ord fourth-quarter results, with profits at $11.2 million (31 cents) compared with $9.008 million (25 cents) a [TEXT OMITTED FROM SOURCE]

The corporation also reported a rec- [TEXT OMITTED FROM SOURCE] year earlier. Sales for the period totaled $273.78 million compared with $255.6 million for the same period a year ago.

President J. W. Marriott Jr. attributed the gains to "an outstanding year - all year long" - turned out by the hotel division, while the restaurant group had "an excellent second half after a slow start."

The hotel group registered an occupancy rate of more than 80 per cent for the year at higher room rates, he said, which contributed to a 47 per cent profit rise for the division.

He noted that the once-troubled Sun Line Cruises group turned out a profitable year after suffering heavy losses in 1976. "We have a profit swing of $1.7 million," Marriott said.

The company's theme parks nearly doubled their profit contribution in 1977, although attendance at both the Santa Clara, Calif., and Chicago parks was virtually unchanged.

The president cautioned investors that fiscal 1973 quarterly results will include "modest distortion" because of an accounting change for investment tax credits. He said the new rule is expected to reduce second-quarter results.

He said the outlook for 1978 continues to be good. The year "shapes up as another record-breaker. In 50 years, we have grown from a single root beer stand to an international factor in lodging, food and leisure time services," Marriott asserted.