The percentage of Americans a month or more late in making their mortgage payments inched up to 5.80 percent in the first three months of the year from 5.72 percent in the last quarter of 1985, according to a new survey by the Mortgage Bankers Association of America.

Over the same time periods, the share of foreclosures started edged ahead from 0.21 percent of all loans to 0.24 percent, according to the survey. Mortgage payments 60 days or more late also increased, from 1.91 percent to 1.95 percent.

Warren Lasko, MBA's executive vice president, said the figures showed that "we still have areas of substantial weakness in the economy, particularly in the energy, agriculture and heavy-industry sectors. Job layoffs in these areas are causing homeowners to miss mortgage payments."

In the January-to-March period, 8.09 percent of District of Columbia mortgage payments were 30 days or more overdue, while 4.9 percent of Maryland borrowers were late with payments and 4.01 percent were late in Virginia. Alaska's delinquency rate, 10.02 percent, was the nation's worst; and New Hampshire's, at 3.01 percent, the best.

Government agencies regularly sell their surplus property, with much of it often times of dubious value. But if your dream is to own an island, the Saint Lawrence Seaway Development Corp. has the perfect gift idea.

The Saint Lawrence agency, part of the U.S. Department of Transportation, is selling Stony Crest Island, 0.8 acre that is part of the Thousand Islands section of the Saint Lawrence River in upstate New York. The island, with trees and brush on it, is above water level, permitting construction of a cottage or seasonal home, the agency says, but there are no utilities on the island, and it's a 10-hour drive from Washington.

The island was bought by a General Motors Corp. executive in 1928, when it was known as Jewel Island, and had a 24-room mansion, boathouses and docks. In 1941, the owner changed the name to Stony Crest, and 15 years later the Saint Lawrence Seaway agency bought the property.

But the mansion was razed as the nearby navigation channel was built. The island has been uninhabited since 1956 and only used as the site of a lighted navigational aid.

Bids for the island are due by July 2, with a minimum offer of $40,000 required.

IN THE BUSINESS . . . Bruce C. Foster and Dean P. Yeonas have formed Foster/Yeonas Cos., a residential development firm, in conjunction with Mission Viejo Co., the home building subsidiary of Philip Morris Co. . . . Edw. R. Carr and Associates Inc., which has been building homes in the Washington area since 1925, recently sold its 7,000th home . . . Donohoe Construction Co. has started construction of the first portion of the Smoketown Plaza Shopping Center in Dale City . . . Metropolitan Partnership has started construction of the Interstate 95 Corporate Center in Newington, which is planned to include three two-story buildings totaling 210,000 square feet of space . . . Rouse & Associates is expanding the Ammendale Technology Park in Prince George's County from its current 167,000 square feet to 486,500 square feet in the next year . . . Suburban Maryland Building Industry Association is hosting a free course on how to buy a home next Wednesday from 7 to 9 p.m. at the Ramada Inn at 4050 Powder Mill Rd. in Beltsville . . . A $500,000 grant from the J. M. Kaplan Fund will be matched with an equal amount of risk capital from NCB Development Corp. to finance construction of cooperative housing for the elderly. The National Cooperative Business Foundation will administer the work. Jacob M. Kaplan, 94, endowed much of his fund with the proceeds of the transformation of Welch's Grape Juice Co., which he headed for years, into a growers' cooperative . . . Winchester Homes Inc., a large Montgomery County builder, and Scarborough Homes, which builds in Northern Virginia, are merging. They both are part of Weyerhaeuser Real Estate Co. . . . Oxford Development Corp. has started construction on the 182-unit second phase of Jonathan's Keepe apartment complex in Reston . . . Lorraine D. Bialy of Hyattsville has been elected president of the National Society of Professional Resident Managers . . . Stout & Teague Cos. has bought the office building at 1325 Massachusetts Ave. NW on Thomas Circle for $6.5 million from the American Federation of Government Employees.