The Federal Power Commission yesterday took a number of steps to get emergency supplies of natural gas to users east of the Rocky Mountains hard-hit by the severe cold spell.

The agency also set up a 24-hour watch on electricity and natural gas shortages for the duration of the emergency.

In another move aimed at easing the natural gas shortage, President Carter's White House energy chief James R. Schlesinger has invited major pipeline company executives to a special meeting this afternoon, reportedly to urge them to share supplies with each other to help high-priority users such as hospitals and homes.

Many of the top officials of the Federal Power Commission worked on the inaugural-day holiday to try to figure out ways to get natural gas supplies to pipelines without adequate amounts of the fuel. Since last week, the commission has been approving emergency orders to get gas from areas where needs are not critical to regions where they are.

Yesterday the commission said it:

Gave Transcontinental Gas Pipe Line Corp., which supplies a small amount of Washington's natural gas needs, permission to take out about 3 billion cubic feet of "base gas" from one of its storage field. It provides a cushion and ensures that there is sufficient pressure to get working gas out of the field and into pipelines.

Transco serves natural gas distribution companies in Alabama, Georgia, Louisiana, Maryland, Mississippi, New Jersey, New York, North Carolina and Pennsylvania. It provides about 15 per cent of the gas distributed by the Washington Gas Light Co. Companies which use this base gas will have to replace it and then some next summer, the FPC said.

Permitted Southern Natural Gas Co. to buy up to 100 million cubic feet of gas a day from the Florida Gas Transmission Co., which will switch to fuel oil for 30 days.

The agency also allowed Southern - which serves Alabama, Georgia, Louisiana, Mississippi, South Carolina and Texas - to bto 50 million cubic feet of gas.

Gave East Tennessee Natto 50 million cubic feet of gas.

Gave East Tennessee Natural Gas Co. authority to purchase 1.5 billion cubic feet of gas from producers in Louisiana and Texas for 60 days at prices well-above the interstate regulated price of $1.42 per thousand cubic feet. East Tennessee, which serves Tennessee and' Virginia, will pay between $2.25 and $2.37 for the unregulated, intrastate gas.

The power commission also allowed Columbia Gas Transmission Corp. to transport 2 million cubic feet a day for high-priority industrial use at the Jones & Laughlin Steel Corp. plant in Alquippa, Pa., and allowed a three-way exchange of gas by pipeline companies in the South to get fuel supplies of up to 1 million cubic feet a day to users in eastern Arkansas.

The 24-hour monitoring system set up by the FPC is designed to help the commission come to grips quickly with problems such as "operating difficulties, changes in gas supply, storage inventroy levels, curtailment actions and emergency service to prevent irreparable damage to life and property."

FPC officials also will attend today's White House meeting, along with the heads to House and Senate subcommittees in charge of natural gas legislation, Rep. John Dingell (D-Mich.) and Sen. Adlai Stevenson III (D-Ill.).

Sen. John Glenn (D-Ohio), has introduced a bill that would allow the President to declare a natural gas emergency, permitting the FPC to shift natural gas from pipelines with little shortage to those facing grave shortages.

An aide to Dingell said there has been little sharing of gas so far because without government action, "pipelines may be subjecting themselves to legal liabilities." The FPC has asked for similar legislation in the past.