New York City Talks remained stalled on two fronts yesterday amid growing concern that the delay in reaching agreement on outstanding labor and financial issues could jeopardize passage of federal loan guarantee legislation.

Treasury Secretary W. Michael Blumenthal and a top aide met with Mayor Ed Koch yesterday morning to get an update on developments and to spur the negotiations which were to have concluded last Saturday.

Blumenthal was at a meeting with Koch and Gov. Hugh Cary two weeks ago when they set the May 20 deadline as a prelude to hearings on the loan guarantee legislation which Senate Banking Committee Chairman William Proxmire (D.-Wisc) scheduled for later this week.

"It would be fair to say that the secretary's opinion is that it's vital that a settlement be reached by today or tomorrow," said Barry Feinstein, who also talked to Blumenthal, and who is president of the Teamsters Union local. Feinstein is one of three union leaders negotiating with the city on behalf of 200,000 municipal employes.

Mayor Koch appeared to be philosophical bout missing the self-imposed May 20 deadline. "Even though we did not meet it, it was your helpful and we've come a long way," he said.

There was some concern, however, that the city appeared to be in confusion and that the Senate Banking Committee hearings necessary to advance the legislation to guarantee $2 billion in loans to New York City could be turned to its disadvantage.

Proxmire, the major congressional opponent to the further federal assistance to New York City, had conditioned the Senate hearings on obtaining commitments from the local parties on New York City's four-year budget and financing package. He is supposed to announce this morning whether he will go ahead with the sessions anyway.

"I think you reach a point where it's not in the city's interest to hold hearings," said an aide to the senator.

This view was echoed by Felix Rohatyn, chairman of the MunicipalAssistance Corp.

York City expires June 30, which is the firmest deadline for another bankruptcy cliffhanger because the city expects to run short of money soon after that.

Meanwhile, the city faces some difficulty this week if the city employe pension funds balk at buying another $683 million in bonds, as they agreed to do in 1975. Controller Harrison Goldin is considering delaying payment of some routine city bills in order to meet two city payrolls. But union leader Victor Gotbaum indicated over the weekend that the pension funds would meet their commitment.

The labor contract talks resumed yesterday afternoon after a weekend recess. The city and the unions reportedly are close on the overall size of a wage settlement. The city is offering 8 percent over two years, and the unions are seeking 9 percent. But sources said the difficulty is that individual unions have substantially differing requirements on the many side issues.