An anonymous buyer bought almost a quarter of Depa's shares valued at US$65 million yesterday.
According to market data 150 million Depa shares were sold in blocks at 44 cents a share to the anonymous investor.
Shares in the Nasdaq Dubai quoted company rose from 30 cents a share on Tuesday to 44 cents at the close yesterday as news of the potential takeover spread.
In a statement published on the Dubai bourse, Depa said it had "reason to believe that an unknown Dubai or Abu Dhabi-based entity wishes to acquire a sizeable stake in its ordinary shares off market".
A spokesman for Depa's external public relations team said the company was unaware of the identity of the mystery investor.
However, analysts speculated that the buyer was possibly an Abu Dhabi government entity.
"My guess would be that an Abu Dhabi government entity is looking to take over an interior design company," said Saleem Khokar, the head of equities at National Bank of Abu Dhabi.
"There are a lot of new schemes coming out of the ground in the capital at the moment and it would make sense for them to make a play for Depa to fulfil that need."
Like most interior fit-out specialists, Depa suffered losses during the global financial crisis as Dubai developers delayed and cancelled projects. Last year, a dispute with Emaar over its work on Burj Khalifa bit deep into profits after work on the prestigious scheme was delayed.
However, in recent years Depa has attempted to diversify its portfolio, acquiring Design Studio, an interiors firm based in Singapore, and Depa is also expanding in Asian markets.
This month, the company announced it had won a Dh93.5m contract to fit out the 400-room Hilton Hotel in Abu Dhabi, part of the Al Forsan International Sports Resort development.