NEW YORK (AP) _ KLM Royal Dutch Airlines has joined a bid by Los Angeles investor Alfred Checchi to buy NWA Inc., the parent of Northwest Airlines, a KLM spokesman confirmed today.

NWA stock rose $1.37 1/2 to $108.75 today in early composite New York Stock Exchange trading.

KLM has ''a commitment to an American investment group headed by Mr. Alfred Checchi to take an indirect interest in a company to be formed by Mr. Checchi that will issue a bid for Northwest Airlines,'' spokesman Peter Wellhuener said.

Wellhuener refused any further comment, citing the confidentiality of the agreement between Checchi, a former hotel executive, and KLM, which is based in Amsterdam, the Netherlands.

The other bidders for St. Paul, Minn.-based NWA are Pan Am Corp., which has offered about $110 a share, or $3.3 billion, and Marvin Davis, the billionaire Los Angeles investor.

The size of the bids by Davis and Checchi were not known.

Kohlberg Kravis Roberts & Co., the leveraged buyout specialist, is also rumored as a possible bidder for NWA.

Checchi is a former Marriott Corp. executive and was associated with the Bass brothers' investment operations. He has two other former Marriott executives as partners: Walt Disney Co.'s chief financial officer, Gary Wilson, and Washington investment banker Fred Malek.

The group also includes Elders IXL Ltd., a diversified Australian company.