The District of Columbia government has asked the U.S. Treasury to send it a $17.1 million installment on the federal payment two weeks earlier than scheduled. Without the speeded-up installment, the city will not be able to pay all its March bills and could wind up the month with a $15 million budget deficit, D.C. Comptroller Al Hill said yesterday.

Hill said that if the money is not received during the third week of March, as requested, the District would again have to postpone paying Metro operating subsidies that are already overdue and also would be required to delay paying other bills for an additional two weeks.

"The city is in a tight financial position right now. This is one of the tough periods [of incoming revenues]," Hill said. "I think that the fair assessment is that we'd probably have to end up paying Metro later. Everybody can't be paid timely . . . You'd just have to hold some of the bills for two weeks."

The federal payment is the annual U.S. government appropriation to the District to compensate for the loss of revenues from tax-exempt federal property and to subsidize the expense of additional city services incurred by Washington because it is the nation's capital.

The $17.1 million installment payment ordinarily would be paid on April 1. Hill said yesterday, however, that the city requested in a a March 4 letter that the payment be made sometime during the third week of March.

Walter L. Jordan, assistant comptroller for finance at the Treasury Department, said the letter had been received and the request sent to the Office of Management and Budget. An OMB official said that no action has yet been taken on the District's request, but he predicted it was likely to be approved.

A $15 millon shortage at the end of the month would come at a crucial time for the city. Teacher paychecks totaling $3 million are to paid March 31. On April 1 the District is to pay $12 million to welfare recipients, about $10 million to pensioners and $9 millon to one group of city employes. The remaining employes, whose pay totals about $5 million, are to be paid three days later, according to Hill.

Neither paychecks nor welfare payments would be postponed, Hill said.

Metro officials said that without timely payment of the money owed by the city -- about $16.4 million, when federal grants and credits are eliminated -- it would have to borrow money to pay its own operating costs, which ordinarily are paid in part through the District's payment to Metro.

"We'd have rather serious cash-flow problems," Delmer Ison, secretary-treasurer of the regional transit authority, said yesterday.

The city's inability to pay its bills without borrowing from future revenue sources underscores the cash-flow problem that some municipal money watchers said they fear could be one of the most serious facing the District government.

Pinched by shortages from earlier estimates used to balance its budget and hampered by its inability to overdraw its checking accounts at private banks the way it could do with the U.S. Treasury until 1978, city officials are regularly scrambling to make ends meet.

Two weeks ago the city borrowed $20 million from the U.S. Treasury to help it pay bills through lean times. On March 2 it paid out more than $1 million through the locally funded general public assistance program with no idea of where the money for April payments would come from. The $6.7 million fund was exhausted.

Hoping to bridge a potential budget gap of $172.4 million caused by over-spending, revenue shortages and recent court decrees striking down previous tax payments to the city, Mayor Marion Barry has proposed $24.1 million in new and increased taxes and fees. Barry also has targeted $26.1 million in spending reductions to be achieved mainly through the elimination of 1,221 jobs on the District payroll.

Barry ordered a March 1 freeze on all new hiring and promotions, and last week asked Congress for an unprecedented $300 million federal payment. So far, only $232 million has been appropriated in any case. In a television appearance last week, Barry threatened to cut off payments to pensioners if Congress does not grant the full amount he has requested for that purpose, and he said he would begin layoffs of up to 5,000 city employes if the City Council does not approve his tax package by May 1.

Most of Barry's proposals will not begin to realize substantial savings until later, however.

Hill said yesterday that the District expects to reach a high point of revenue collections later in April. But by the end of the summer, payments again will fall off, he said.

Already, he said, the city has $40 million in outstanding loans from the U.S. Treasury -- including $20 million originally scheduled to be repaid six months ago.

Hill said that for several months since Oct. 1 the District has been hampered in its ability to monitor spending properly because a newly installed computerized financial management system has not been functioning properly.