MADRID, March 17 (Reuters) - Spanish engineering and energy firm Abengoa SA said on Wednesday its Abenewco1 holding company had requested a 249 million euro ($297 million) temporary state aid package to stay afloat while it evaluates a non-binding takeover bid.

In early February, parent company Abengoa SA voluntarily started a bankruptcy process after its creditors refused to extend a deadline for negotiating a restructuring agreement.

Abenewco1, which holds most of its parent company's assets and liabilities and employs most of the group's 13,500 workers, was not part of the insolvency proceedings.

A proposed restructuring to tackle Abengoa's 6 billion euro debt mountain unravelled in February after the regional government of Andalusia withdrew an offer of 20 million euros in funding as part of a 250 million euro overall deal.

The Seville-based business had borrowed heavily in the preceding decade to fund an aggressive expansion into clean energy from its traditional infrastructure projects.

On Wednesday, Abengoa said as part of a new transaction, Abenewco1 had received a non-binding offer from a group of investors led by Los Angeles-based private equity fund TerraMar Capital LLC, which aims to control 70% of the company after subscribing to a 50 million euro capital increase.

The offer consists of a 150 million euro loan divided into a 35 million euro short-term liquidity line and an additional disbursement of 115 million euros.

Abengoa said TerraMar's financing and investment offer was conditional on it securing new financing and new bonding lines, in line with previous agreements announced in August 2020.

In early August, the company secured a complex deal with its creditors guaranteeing state financing of up to 250 million euros and a bonding line of 300 million.

Abenweco 1 said on Wednesday that the new refinancing plan based on the non-binding offer was "the only feasible option".

($1 = 0.8398 euros) (Reporting by Jesús Aguado; Editing by Andrei Khalip, Nathan Allen and Jan Harvey)