Shares in Polish chemicals producer Ciech surged nearly 8% after its biggest shareholder KI Chemistry said on Monday it plans to run a tender offer to buy the rest of the shares and take full control.

KI Chemistry, owned by Kulczyk Investment Group, said it planned to buy 25.7 million Ciech shares at 49.00 zlotys ($10.97) to increase its stake from over 51% currently to 100%.

At 0820 GMT Ciech shares were up 7.7% at 51.25 zlotys.

The tender offer is expected to be announced in the first half of March, KI Chemistry said in its statement.

"(The) operation of Ciech S.A. in the non-public company formula will ensure the possibility of faster and more flexible responses to dynamically changing economic, regulatory and geopolitical conditions," KI Chemistry said.

It also said that increasing the competitiveness and further development of the CIECH Group may require significant capital expenditures, including for the implementation of a comprehensive technological and energy transformation. ($1 = 4.4650 zlotys) (Reporting by Maria Gieldon in Gdansk; Editing by Susan Fenton)