National Public Radio soon may be forced to lay off nearly 10 percent of its 400 Washington-based employes. The reason, according to NPR President Frank Mankiewicz: lower-than-expected income from private-sector underwriters, and governmental delays in deregulation needed to implement some innovative revenue-producing businesses.

"I don't know what form the cutbacks are going to take," said Mankiewicz yesterday. "Our finance committees are coming in for a bunch of meetings and we'll probably know about it by next week. There will, I certainly think, be some cutbacks. I would hope that attrition and a freeze on hiring would take care of some positions. But with seven months to go in the year, we can cushion it a little more in terms of its impact on programming."

Mankiewicz pointed to several factors, starting with federal cutbacks in 1981 that spurred NPR's development of a five-year plan to abandon its dependence on federal funding entirely. That plan included a major underwriting campaign from corporations and foundations and a number of co-ventures in the communications field.

NPR provides news, commentary, and performance programs to 280 member stations through shows such as "All Things Considered," "Morning Edition," and "The Sunday Show."

Even though federal funding had dropped to $11.5 million in fiscal 1983 (compared with $14.5 in 1981), NPR raised its 1983 budget to $25, from $21 million in 1982. (The 1981 figure was $19 million.) "We thought we would realize revenues and grant income in that amount," Mankiewicz said. "We weren't counting on a lot of revenue from sources that needed government approval."

In its first year, the underwriting campaign, in which news/information and performance shares were purchased by major businesses, brought in $2.9 million. In the first five months of fiscal 1983, the program has brought in $3.4 million. But because of the recession, says Mankiewicz, "We're getting a good number of corporations and foundations, but they're not giving as much as we had thought they would. There was an increase in the first five months, but our target was higher. The recession has held back a lot of companies who said, 'Yes, we want to support you' and now they're saying, 'Let's wait till the third quarter.' "

Mankiewicz pointed out that this fiscal year's NPR budget was set last April, "a full year ago. At that time things looked better than they do now; people said the economy is up, inflation is down and things will take off and we had reason to believe that we would do more underwriting than we have. We've done well, but we haven't done well enough." He added that the shortfall could account for 5 to 10 percent of the budget.

A second block has come from delays in getting an FCC ruling on deregulation of subcarriers, the unused portion of the FM radio band. While NPR has been successful in leasing time and channels on its satellite (it now distributes all of Muzak), several other co-ventures, including a national paging system, a teletext system and a hand-held radio that would provide printouts on such non-broadcast information as stock market quotations, sports scores and airline schedules, depend on the FCC's approval of deregulation.

According to Mankiewicz, deregulation got derailed because of objections raised by radio-reading services for the blind, which use subcarriers (with intervention from the Corporation for Public Broadcasting, NPR's parent body, one channel has now been set aside). Another problem arose over common carriers in the paging areas, "something that doesn't involve us at all," said Mankiewicz. "I feel confident it will come out in a way that will permit us to go into business, that it can be good or it can be terrific. Nobody's conspiring against us. It's just become more difficult and our partners and their investors are holding back, that's all. Our hope hasn't been dashed, it's been delayed."

The budgeting problem, he added, is not really a problem except for the next six months. "We've got a fiscal year and a budget and we have to adapt it like everything else. The problem is not uncommon in public broadcasting. It's going on all over the place. We may be a little late to see how tough the recession has made it these last couple of years, particularly combined with cuts in funding. Those we could have handled, but the slowdown in the economy has been too deep and too long."

Mankiewicz said that the problems have not affected NPR's plans for financial independence by 1988. "There's no change in our objective to be free of federal funding by then. We're going through a narrow channel and the channel is narrowing on us, but we have no doubt about what's on the other end."