The stock market suffered its largest loss of the year yesterday in selling that left the Dow Jones industrial average at a new 15-month low.

Analysts traced the decline to the Carter administration's upward revision of its inflation forecast for the year.

The Dow average of 30 blue chips dropped 12.47 to 914.60, for its biggest setback since it fell 17.37 points last Nov. 5. It was the lowest close for the average since it finished at 912.94 on Jan. 13, 1976.

Declines overwhelmed advances by a 4-1 margin in the broad tally on the New York Stock Exchange. NYSE volume totalled 20.44 million shares, against 20.70 million Friday.

Much of the trading reflected renewed inflation fears following the weekend announcement by the Office of Management and Budget of an increased projection of the rise in the consumer price index this year from 5.3 to 6.7 per cent. The budget office also slightly lowered its estimate the economic growth rate for the year.

Analysts noted that the news magnified the market's struggle with the uncertainty of the effects of President Carter's energy proposals. The Dow fell 20.69 points last week.

Standard & Poor's index of 400 industrials dropped 1.29 to 107.76 on the day, and S&P's 500-stock composite index was down 1.11 at 97.33.

Eastman Kodak, one of several big name glamor issues that hit new lows for the year last week, again was the major contributor to the Dow's decline. The stock fell 4-1/8 to 60-1/8 following the company's report of a 20 per cent decline in first-quarter earnings.

Polaroid, by contrast, rose 1-1/8 to 33-1/8. The company is expected to introduce an instant motion-picture system today.

For the second consecutive session, S.S. Kresge, which fell 1/4 Friday, was the most active NYSE-listed issue at 4 p.m. EST., losing 1 1/4 to 27 7/8. Other retail issues were weaker following an 0.9 per cent dip in retail sales last week. Sears, Roebuck lost 1 to 54 1/4. There is some question whether consumer confidence has softened recently.

General Electric, another blue-chip, was the third most active issue, off 1 7/8 to 51 1/2. Exxon, another Dow component, lost 1 to 50 7/8 after the oil giant reported lower first quarter earnings. Other oils generally were lower in light of the energy program outlined by Carter last week.

Phillips Petroleum plunged 4 1/2 to 53 in active trading. A Phillips well blew out in the North Sea late Friday, the first major oil spill in the area and one of the worst on record.

Big Three industries fell 1 to 29 1/4; Cummins Engine 1 1/8 to 51 5/8, Asarco 7/8 to 20 1/2, Foster Wheeler 3/4 to 23 3/4, Varian Associates 5/8 to 18 1/8 and Merck 3/4 to 50 3/8. All the firms reported higher earnings.

American Hospital Supply lost 2 to 22 3/8, Kaneb Services 2 1/4 to 35 5/8, Union Oil of California 1 1/4 to 51 and Washington Steel 5/8 to 20. Each of the companies reported lower earnings.

The Carter administration's proposal to put a 9 per cent ceiling on health care cost increase sent hospital management stocks skidding. American Medical International dropped 1 1/4 to 12, Humans 1 3/8 to 15 3/4, Hospital Affiliates 1 to 19 and Hospital Corp. of America 7/8 to 23.

Gerber Products lost 3/4 to 37 3/4 and Anderson Clayton 1 to 24 5/8. Gerber directors said they would file suit to block Anderson Clayton's recently announced takeover bid. But Anderson Clayton said yesterday it wasn't backing down.

The American Stock Exchange index gave up 0.90 to 110.85 and the average price of a common share lost nine cents. Declines routed advances, 433 to 163, among the 586 issues traded. Volume at 4 p.m. totaled 2,030,000 shares, compared with 20,380,000 Friday.

Houston Oil & Minerals was the most active Amex-listed issue, off 3/4 to 44 5/8. Kaiser Industries followed, off 5/8 to 18. Husky Oil was third, off 3/8 to 26 1/4.