The stock market posted its second straight loss today amid worries about the outlook for the dollar and interest rates.

A late round of buying concentrated in blue chips enabled the market to finish well above its midsession lows, however.

The Dow Jones average of 30 industrials, down about 20 points at one stage, finished with a 1.37 loss at 1,829.61. The average took a 24.92-point drop Tuesday. Volume on the New York Stock Exchange slowed to 149.69 million shares from 161.51 million Tuesday.

As the dollar tumbled Tuesday in foreign exchange, bond prices fell and interest rates rose in the credit markets. Today, prices of long-term bonds dropped another $10 to $15 for every $1,000 in face value.

Analysts said traders were concerned that a declining dollar would dampen foreign demand for U.S. securities such as Treasury bonds.

Furthermore, some observers believe that at some point the dollar's drop might prompt the Federal Reserve to start trying to support the currency by moving toward a more restrictive credit policy.

Brokers said those concerns were enough to prompt investors to cash in their gains from the market's dramatic rise over the past seven months.

On the trading floor, Manville was the most active NYSE-listed issue, down 2 1/8 to 3 1/8. The company Tuesday said it altered its reorganization plan to benefit creditors at shareholders' expense.

Bank stocks showed fractional losses. Citicorp dropped 3/4 to 61 5/8; Chemical New York 3/8 to 54 5/8; J. P. Morgan 3/8 to 85 3/4; and Chase Manhattan 3/8 to 48 1/8.

Among other interest-rate-sensitive issues in the savings and loan sector, Great Western Financial fell 2 to 42 3/4 and H. F. Ahmanson 1/2 to 64 1/8.

Losers among the blue chips included American Express, down 2 1/2 at 62 7/8; Sears Roebuck, down 5/8 at 44 3/8; and International Paper 1 1/2 to 59 3/4. By contrast, International Business Machines rose 2 1/4 to 155 1/4.

Auto stocks were mixed as domestic car manufacturers reported a 23.5 percent decline in mid-April sales. Ford Motor lost 3/4 to 83 3/4 and Chrysler dropped 1 5/8 to 38 1/4, while General Motors was up 1/2 at 81 7/8.

Black & Decker climbed 3 to 24 1/2 in active trading on merger rumors and speculation. The company said it knew of no explanation for the activity.

Eastern Airlines rose 1/2 to 8 5/8. There were reports that the company, which is slated to merge with Texas Air, has been approached by the Pritzker family of Chicago about a possible competing takeover bid.

Sun Chemical was up 2 3/4 to 66 3/4. The company said Tuesday it had received an unsolicited letter from Dainippon, in which the Japanese company proposed to negotiate with Sun for the acquisition of the company's graphic arts materials group for $425 million in cash or for the entire company at $77 per share in cash. The offer is under review.

In the overall tally on the Big Board, about five issues declined in price for every three that gained ground. The exchange's composite index dropped 0.52 to 139.34.

Nationwide turnover in NYSE-listed issues, including trades in those stocks on regional exchanges and in the over-the-counter market, totaled 175.49 million shares.

Standard & Poor's index of 400 industrials lost 0.45 to 301.00, and S&P's 500-stock composite index was down 0.67 at 241.75.

The Nasdaq composite index for the over-the-counter market dropped 1.43 to 389.05. At the American Stock Exchange, the market value index closed at 271.49, down 1.04.