FILE PHOTO: The Goldman Sachs company logo is seen in the company's space on the floor of the New York Stock Exchange, (NYSE) in New York, U.S., April 17, 2018. REUTERS/Brendan McDermid/File Photo

MADRID (Reuters) - Goldman Sachs has raised its stake in Spanish supermarket chain DIA DIDA.MC to 15.8 percent from 14.5 percent, a regulatory filing showed shortly after the discounter's main shareholder disclosed it had raised its own holding close to the legal threshold for a full takeover bid.

The U.S. investment bank now holds 1.5 percent of DIA directly and 14.3 percent through derivatives, a filing with Spain’s market regulator CNMV showed.

A long economic crisis helped boost DIA’s market share but it has struggled since an economic rebound put more cash in Spaniards’ pockets.

It has lost more than two thirds of its market value since its 2015 peak.

Last week, shareholder LetterOne, controlled by Russian tycoon Mikhail Fridman, stoked speculation it might launch a takeover bid after it informed the regulator it had raised its stake to 29 percent.

Under Spanish law, an investor must launch a full takeover bid once its stake reaches 30 percent stake.